The components should be configurable independently of the global
scrcpy_options instance: their configuration could be provided
separately, like it is the case for example for some screen parameters.
For consistency, keyboard injection should not depend on scrcpy_options.
There was only two key injection modes:
- the default one
- the mode with --prefer-text enabled
To prepare the addition of another mode (--raw-key-events), use an enum
instead of a bool.
PR #2831 <https://github.com/Genymobile/scrcpy/pull/2831>