CI/CD Gitlab Actions

Some useful items that came out of our automation session:

• Building on Push (tor-browser, mullvad-browser, firefox-android)
  • pull relevant artifacts from last succeeding nightly (toolchains, libs, etc)
• Linting check in MR
• Auto Rebase MR on upstream tag updates
• Integration Tests (tor-browser, mullvad-browser, firefox-anroid)
• TZP Fingerprinting Testing