Project cleanup round 2 (test & perf projects)

[jviau]

Issue describing the changes in this PR

Pull request checklist

IMPORTANT: Currently, changes must be backported to the in-proc branch to be included in Core Tools and non-Flex deployments.

• [ ] Backporting to the in-proc branch is not required
  • Otherwise: Link to backporting PR -- TODO
• [x] My changes do not require documentation changes
  • [ ] Otherwise: Documentation issue linked to PR
• [x] My changes should not be added to the release notes for the next release
  • [ ] Otherwise: I've added my notes to release_notes.md
• [x] My changes do not need to be backported to a previous version
  • [ ] Otherwise: Backport tracked by issue/PR #issue_or_pr
• [x] My changes do not require diagnostic events changes
  • Otherwise: I have added/updated all related diagnostic events and their documentation (Documentation issue linked to PR)
• [x] I have added all required tests (Unit tests, E2E tests)

Additional information

Re-organizes test and perf projects:

• Folder structure updates
  • perf projects moved to /perf
  • All test-resource projects moved to /test/Resources/TestProjects
  • TestScripts moved to /test/Resources/TestScripts
• Removed some explicit files from sln
• Cleaned up test csproj's

[jviau]

/azp run host.public host.integration-tests

[azure-pipelines[bot]]

No pipelines are associated with this pull request.

[jviau]

/azp run host.public

[azure-pipelines[bot]]

Azure Pipelines successfully started running 1 pipeline(s).

[jviau]

/azp run host.integration-tests

[azure-pipelines[bot]]

Azure Pipelines successfully started running 1 pipeline(s).