[S58] O1.1 - Set up QA and regression test infrastructure

• Work with Mozilla to identify if any existing Firefox testing infrastructure can be used to run automated tests on our rebased codebase.
• Evaluate Firefox tests and Try builds to identify any currently broken functionality.
• Audit existing Tor Browser tests to identify which tests are missing and need to be written; audit existing Firefox tests to determine which tests need to be disabled because they test undesired behavior in Tor Browser.
• Configure integration testing infrastructure.
• Fix existing regression tests that are currently failing after testing and audits.

• Fix Tor Browser testsuite
• Fix tor-browser tbb-tests
• Evaluate Firefox tests