Add tests for "Should Trusted Type policy creation be blocked by Content Security Policy" in workers

[fred-wang]

cc @lukewarlow

See

https://w3c.github.io/trusted-types/dist/spec/#should-block-create-policy
https://w3c.github.io/trusted-types/dist/spec/#trusted-types-csp-directive

For a quick search, I don't see anything involving workers:

find -type f | xargs grep "trusted-types" | grep -v "require-trusted-types" | grep "Content-Security-Policy"
./trusted-types-reporting.html.headers:Content-Security-Policy: trusted-types one
./trusted-types-reporting.html.headers:Content-Security-Policy-Report-Only: trusted-types two; report-uri /content-security-policy/resources/dummy-report.php
./trusted-types-reporting-check-report.html.sub.headers:Content-Security-Policy-Report-Only: trusted-types one two; report-uri /reporting/resources/report.py?op=put&reportID={{$id}}
./trusted-types-duplicate-names-list-report-only.html.headers:Content-Security-Policy-Report-Only: trusted-types a b c
./TrustedTypePolicyFactory-createPolicy-cspTests-noNamesGiven.html:<meta http-equiv="Content-Security-Policy" content="trusted-types">
./trusted-types-duplicate-names-list.html:  <meta http-equiv="Content-Security-Policy" content="trusted-types a b c">
./trusted-types-report-only.html:  //   Content-Security-Policy-Report-Only: trusted-types ...; report-uri ...
./TrustedTypePolicyFactory-createPolicy-cspTests.html:<meta http-equiv="Content-Security-Policy" content="trusted-types SomeName JustOneMoreName AnotherName">
./TrustedTypePolicyFactory-createPolicy-cspTests-none-none-name.html:<meta http-equiv="Content-Security-Policy" content="trusted-types 'none' 'none' SomeName">
./trusted-types-tojson.html:  <meta http-equiv="Content-Security-Policy" content="trusted-types foo">
./TrustedTypePolicy-CSP-no-name.html:<meta http-equiv="Content-Security-Policy" content="trusted-types">
./TrustedTypePolicyFactory-blocking.tentative.html:<meta http-equiv="Content-Security-Policy" content="trusted-types *">
./trusted-types-duplicate-names-list-report-only.html:// Content-Security-Policy-Report-Only: trusted-types a b c
./TrustedTypePolicyFactory-createPolicy-cspTests-none-none.html:<meta http-equiv="Content-Security-Policy" content="trusted-types 'none' 'none'">
./TrustedTypePolicyFactory-createPolicy-cspTests-none.html:<meta http-equiv="Content-Security-Policy" content="trusted-types 'none'">
./TrustedTypePolicyFactory-createPolicy-cspTests-none-skip.html:<meta http-equiv="Content-Security-Policy" content="trusted-types * 'none' 'allow-duplicates'">
./trusted-types-reporting.html:  //   Content-Security-Policy: trusted-types one
./trusted-types-reporting.html:  //   Content-Security-Policy-Report-Only: trusted-types two; report-uri ...
``̀`