Allow users to change keybinds in settings

[noah-curran]

Something that came up in #434 was a questioning over suitable keybinding. A user may ultimately decide a certain set of keybinding makes sense for their workflow/keyboard locality. The code commit for #434 includes code for changing the keybinding in the settings alongside a preset default keybind.

The other plugins and components of Tabliss should probably also be allowed to change their keybindings according to user preferences, all within a consolidated global keybinding setting. This global keybinding setting should enforce that the keybindings for various shortcuts for actions should also not overlap with one another. As a result, the code included in #434 would not be sufficient for this, but possibly used as a starting point.