This opens a searchable list (similar to what we have for display
objects), which shows a tree of Domains and their associated classes.
Currently, clicking on the domain/class buttons doesn't do anything.
In a follow-up, I'm planning to add additional windows to display
information about a class.
The desktop version of Ruffle now has a volume controls window. It can
be accessed through the menu bar (Controls > Volume controls).
It contains a mute button and a slider from 0 to 100.
The volume settings set in the GUI are saved in a new VolumeControls
struct, which is also used to calculate the real volume (adapted for
logarithmic hearing) out of the entered volume and the mute checkbox.
As soon as the volume is changed in the GUI, the real volume will be set
in the player (if the player exists).
The player doesn't set its volume level according to the PlayerOptions
after its creation anymore. Instead, RuffleGui::on_player_created now
gets the player and sets its volume to the real volume set in the GUI.
The volume in the GUI itself defaults to the PlayerOptions value.
This also fixes the issue that the PlayerOptions volume has previously
not been adapted for logarithmic hearing.
The existing ftl files have been adapted (and new ones have been
created) to include the new multilingual text in the menu bar and the
volume controls window.