Make BundlerConsistencyTests stop building/copying self-contained project unnecessarily

[elinor-fung]

BundlerConsistencyTests were building a self-contained project and copying it for each test case. They are targeting the Bundler API and don't actual need a full app - just validation of how things get bundled and added to the manifest.

• Add a HelloWorld project for as a pre-built test asset for host tests
• Make BundlerConsistencyTests use a pre-built app and shared framework files instead of building/copying a self-contained project
• Move the one test TestWithAdditionalContentAfterBundleMetadata that actually runs the bundled app into BundleAndRun

Contributes to #91039 - the other two test classes related to that issue are:

• BundledAppWithSubDirs: should already be addressed with Switch the AppWithSubDirs project used for single-file tests to project that is built outside of test runs #91477
• BundleExtractToSpecificPath: should switch to using SingleFileTestApp helper and the HelloWorld project being added in this PR

[ghost]

Tagging subscribers to this area: @agocke, @vitek-karas, @VSadov
See info in area-owners.md if you want to be subscribed.

Issue Details

---

BundlerConsistencyTests were building a self-contained project and copying it for each test case. They are targeting the Bundler API and don't actual need a full app - just validation of how things get bundled and added to the manifest.

• Add a HelloWorld project for as a pre-built test asset for host tests
• Make BundlerConsistencyTests use a pre-built app and shared framework files instead of building/copying a self-contained project
• Move the one test TestWithAdditionalContentAfterBundleMetadata that actually runs the bundled app into BundleAndRun

Contributes to #91039 - the other two test classes related to that issue are:

• BundledAppWithSubDirs: should already be addressed with Switch the AppWithSubDirs project used for single-file tests to project that is built outside of test runs #91477
• BundleExtractToSpecificPath: should switch to using SingleFileTestApp helper and the HelloWorld project being added in this PR

Author:	elinor-fung
Assignees:	-
Labels:	test-enhancement, area-Single-File
Milestone:	-

[vitek-karas]

Thanks!