Refactor XML validation into a class (#214)

Previously, we only had a single static function that read the XML
schema on every XML validation. This change refactors the validation
into a separate class so that the schema does not have to be reloaded.

This is practical for validating a large number of XML samples.

We implement a table-driven test of the validation based on
the XML files directly extracted from the AASXs obtained from
http://admin-shell-io.com/samples/.

The tests revealed an inconsistency between our logic and "official"
AAS XSD schema. The problem could be fixed by "fixing" the XML and
moving the sequence of `AssetIdentificationModelRef` to the end of
XML serialization logic of an asset.

TestResult.xml

@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="utf-8" standalone="no"?>
+<test-run id="0" runstate="Runnable" testcasecount="13" result="Passed" total="1" passed="1" failed="0" inconclusive="0" skipped="0" asserts="0" engine-version="3.11.1.0" clr-version="4.0.30319.42000" start-time="2020-09-29 08:11:39Z" end-time="2020-09-29 08:11:43Z" duration="3.657159">
+  <command-line><![CDATA["C:\MIHO\Develop\Aasx\aasx-package-explorer\tools\NUnit.ConsoleRunner.3.11.1\tools\nunit3-console.exe" artefacts/build/Debug/AasxCsharpLibrary.Tests.dll --test=AdminShellNS.Tests.TestLoadSaveChain.TestLoadSaveXmlValidate]]></command-line>
+  <filter>
+    <test>AdminShellNS.Tests.TestLoadSaveChain.TestLoadSaveXmlValidate</test>
+  </filter>
+  <test-suite type="Assembly" id="0-1018" name="AasxCsharpLibrary.Tests.dll" fullname="C:\MIHO\Develop\Aasx\aasx-package-explorer\artefacts\build\Debug\AasxCsharpLibrary.Tests.dll" runstate="Runnable" testcasecount="13" result="Passed" start-time="2020-09-29 08:11:40Z" end-time="2020-09-29 08:11:43Z" duration="2.386909" total="1" passed="1" failed="0" warnings="0" inconclusive="0" skipped="0" asserts="0">
+    <environment framework-version="3.12.0.0" clr-version="4.0.30319.42000" os-version="Microsoft Windows NT 10.0.17134.0" platform="Win32NT" cwd="C:\MIHO\Develop\Aasx\aasx-package-explorer" machine-name="CDE86488" user="miho" user-domain="FESTO" culture="de-DE" uiculture="de-DE" os-architecture="x64" />
+    <settings>
+      <setting name="DisposeRunners" value="True" />
+      <setting name="WorkDirectory" value="C:\MIHO\Develop\Aasx\aasx-package-explorer" />
+      <setting name="ImageRuntimeVersion" value="4.0.30319" />
+      <setting name="ImageTargetFrameworkName" value=".NETFramework,Version=v4.6.1" />
+      <setting name="ImageRequiresX86" value="False" />
+      <setting name="ImageRequiresDefaultAppDomainAssemblyResolver" value="False" />
+      <setting name="RuntimeFramework" value="net-4.0" />
+      <setting name="NumberOfTestWorkers" value="4" />
+    </settings>
+    <properties>
+      <property name="_PID" value="6440" />
+      <property name="_APPDOMAIN" value="domain-" />
+    </properties>
+    <test-suite type="TestSuite" id="0-1019" name="AdminShellNS" fullname="AdminShellNS" runstate="Runnable" testcasecount="13" result="Passed" start-time="2020-09-29 08:11:40Z" end-time="2020-09-29 08:11:43Z" duration="2.364843" total="1" passed="1" failed="0" warnings="0" inconclusive="0" skipped="0" asserts="0">
+      <test-suite type="TestSuite" id="0-1020" name="Tests" fullname="AdminShellNS.Tests" runstate="Runnable" testcasecount="13" result="Passed" start-time="2020-09-29 08:11:40Z" end-time="2020-09-29 08:11:43Z" duration="2.364241" total="1" passed="1" failed="0" warnings="0" inconclusive="0" skipped="0" asserts="0">
+        <test-suite type="TestFixture" id="0-1012" name="TestLoadSaveChain" fullname="AdminShellNS.Tests.TestLoadSaveChain" classname="AdminShellNS.Tests.TestLoadSaveChain" runstate="Runnable" testcasecount="2" result="Passed" start-time="2020-09-29 08:11:40Z" end-time="2020-09-29 08:11:43Z" duration="2.358844" total="1" passed="1" failed="0" warnings="0" inconclusive="0" skipped="0" asserts="0">
+          <test-case id="0-1015" name="TestLoadSaveXmlValidate" fullname="AdminShellNS.Tests.TestLoadSaveChain.TestLoadSaveXmlValidate" methodname="TestLoadSaveXmlValidate" classname="AdminShellNS.Tests.TestLoadSaveChain" runstate="Runnable" seed="2101435676" result="Passed" start-time="2020-09-29 08:11:40Z" end-time="2020-09-29 08:11:42Z" duration="2.342831" asserts="0" />
+        </test-suite>
+      </test-suite>
+    </test-suite>
+  </test-suite>
+</test-run>

src/AasxCsharpLibrary.Tests/AasxCsharpLibrary.Tests.csproj

@@ -53,6 +53,7 @@
     <Compile Include="TestAdminShellUtil.cs" />
     <Compile Include="TestLoadSaveChain.cs" />
     <Compile Include="TemporaryDirectory.cs" />
+    <Compile Include="TestValidateXml.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\AasxCsharpLibrary\AasxCsharpLibrary.csproj">
@@ -70,12 +71,9 @@
     </EmbeddedResource>
   </ItemGroup>
   <ItemGroup>
-    <Content Include="Resources\schemas\xml\AAS.xsd">
-      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
-    </Content>
-    <Content Include="Resources\schemas\xml\IEC61360.xsd">
-      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
-    </Content>
+    <None Include="TestResources\XmlValidation\expectedOk\**">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </None>
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
@@ -85,4 +83,4 @@
     <Error Condition="!Exists('..\packages\NUnit.3.12.0\build\NUnit.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\NUnit.3.12.0\build\NUnit.props'))" />
     <Error Condition="!Exists('..\packages\NUnit3TestAdapter.3.17.0\build\net35\NUnit3TestAdapter.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\NUnit3TestAdapter.3.17.0\build\net35\NUnit3TestAdapter.props'))" />
   </Target>
-</Project>
+</Project>