Add unit tests for StreamExtensions, #1105

[paulirwin]

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Add unit tests for StreamExtensions

Fixes #1105

Description

Adds some tests adapted from Apache Harmony for the StreamExtensions extension methods.

[NightOwl888]

Thanks for the PR.

I noticed during the review that the below comment is out of date. At one point we used BinaryReader and BinaryWriter, but it was found that they throw exceptions when you are not careful to ensure that surrogate pairs are not split up, which is what prompted the creation of these extension methods.

lucenenet/src/Lucene.Net.Facet/Taxonomy/WriterCache/CharBlockArray.cs

Lines 37 to 40 in 4acbde3

	// LUCENENET NOTE: The serialization features here are strictly for testing purposes,
	// therefore it doesn't make any difference what type of serialization is used.
	// To make things simpler, we are using BinaryReader and BinaryWriter since
	// BinaryFormatter is not implemented in .NET Standard 1.x.