Update UA regex to match TB9 user agent strings

[rocodes]

Status

Ready for review

Description of Changes

Fixes #5052 (for now).

Update User Agent String regex in line with what Tor Browser currently sends. Note that as mentioned in the comments of that issue:

• this will have to be kept up to date as Tor Browser/Firefox update the spoofed navigator.userAgent string
• this will only match users on an up to date version of Tor browser
• this will falsely identify Firefox users who enable privacy.resistFingerprinting as being Tor users.

Testing

• Open Tor Browser and another browser on different platforms and visit Source Interface
• Test when Tor Browser security slider is at "Safest" and also at a lower security setting
• Warning bar should not be present (Safest) or should encourage user to adjust Tor browser security settings (other settings)

Deployment

n/a

Checklist

If you made changes to the server application code:

• Linting (make lint) and tests (make test) pass in the development container

** Note ** I'm having make problems that I suspect are unrelated to this issue, but I don't want to keep being a bottleneck on this while I resolve those.

[zenmonkeykstop]

Tested in:

• Whonix + TBB 9.0.1:
  • standard: security settings message displayed
  • safest: no message displayed
• OS X + TBB 9.0.2:
  • standard: security settings message displayed
  • safest: no message displayed
• Android + Tor Browser:
  • standard: "use tor browser" displayed
  • safest: no message displayed

LGTM (that was the previous behaviour for Android, so no change) based on tests and diff review.