Support mouse back and forward buttons

[CendioOssman]

Is your feature request related to a problem? Please describe.
I'd like to be able to use my mouse to go back and forward in my browser inside my VNC session. Currently that makes my local browser go back and forward instead.

Describe the solution you'd like
See above.

Describe alternatives you've considered
None

Additional context
None

[CendioOssman]

A quick test shows that Chrome forwards these events to us, but not Firefox. Tested on Linux X11.

[CendioOssman]

Issue reported to Firefox:

https://bugzilla.mozilla.org/show_bug.cgi?id=1933746

[CendioOssman]

Server-side support for this is available in development versions of TigerVNC:

TigerVNC/tigervnc#1826

[CendioHalim]

I tested mouse back/forward on:

macOS:

• Safari
  • All buttons after MMB (forward/back/extra etc.) report button 2 (same as MMB).
• chromium:
  • Works as expected, button 3 and 4 for back/forward respectively.
• Edge:
  • Same as chromium
• Firefox:
  • Firefox consumes forward/back events.

Windows 11:

• chromium:

  • Works as expected, button 3 and 4 for back/forward respectively.

• Edge:

  • Same as chromium

• Firefox:

  • Firefox consumes forward/back events.

Linux (Fedora 41, KDE)

• chromium:
  • Works as expected, button 3 and 4 for back/forward respectively.
• Firefox:
  • Firefox consumes forward/back events.