Added Docker build action

[qstokkink]

Fixes #8105

This PR:

• Adds a Docker image build action.

The latest build is available here: https://github.com/qstokkink/tribler/actions/runs/10506075807

[xoriole]

The docker image is requiring the DISPLAY, and is failing with the following stacktrace:

Traceback (most recent call last):
  File "/app/tribler/src/run_tribler.py", line 14, in <module>
    import pystray
  File "/usr/local/lib/python3.10/site-packages/pystray/__init__.py", line 64, in <module>
    Icon = backend().Icon
  File "/usr/local/lib/python3.10/site-packages/pystray/__init__.py", line 56, in backend
    return candidate()
  File "/usr/local/lib/python3.10/site-packages/pystray/__init__.py", line 36, in xorg
    from . import _xorg as backend; return backend
  File "/usr/local/lib/python3.10/site-packages/pystray/_xorg.py", line 36, in <module>
    display = Xlib.display.Display()
  File "/usr/local/lib/python3.10/site-packages/Xlib/display.py", line 89, in __init__
    self.display = _BaseDisplay(display)
  File "/usr/local/lib/python3.10/site-packages/Xlib/display.py", line 71, in __init__
    protocol_display.Display.__init__(self, *args, **keys)
  File "/usr/local/lib/python3.10/site-packages/Xlib/protocol/display.py", line 84, in __init__
    name, protocol, host, displayno, screenno = connect.get_display(display)
  File "/usr/local/lib/python3.10/site-packages/Xlib/support/connect.py", line 73, in get_display
    return mod.get_display(display)
  File "/usr/local/lib/python3.10/site-packages/Xlib/support/unix_connect.py", line 59, in get_display
    raise error.DisplayNameError(display)
Xlib.error.DisplayNameError: Bad display name ""

[qstokkink]

That should be resolved by https://stackoverflow.com/a/44434831

[qstokkink]

Another issue: this build does not package the npm output (yet).