Inject main display events to the original display

When mirroring a secondary display, touch and scroll events must be sent
to the mirroring virtual display id (with coordinates relative to the
virtual display size), rather than to the original display (with
coordinates relative to the original display size).

This behavior, introduced by d19396718ee0c0ba7fb578f595a6553c0458da59,
was also applied for the main display for consistency. However, it
causes some UI elements to become unclickable.

To minimize inconveniences, restore the previous behavior when mirroring
the main display: send all events to the original display id (0) with
coordinates relative to the original display size.

Fixes #5545 <https://github.com/Genymobile/scrcpy/issues/5545>
Fixes #5605 <https://github.com/Genymobile/scrcpy/issues/5605>
Fixes #5616 <https://github.com/Genymobile/scrcpy/issues/5616>
Refs #4598 <https://github.com/Genymobile/scrcpy/issues/4598>
Refs #5137 <https://github.com/Genymobile/scrcpy/issues/5137>
Refs #5370 <https://github.com/Genymobile/scrcpy/pull/5370>
PR #5614 <https://github.com/Genymobile/scrcpy/pull/5614>