This allows removing it from `class_db.h`, significantly reducing the amount of files
that include it transitively.
Also includes some include cleanup in `control.h` and `rich_text_label.h` done while
ensure they don't depend on `callable_mp`.
Currently, when using the stack trace or the remote scene tree and selecting an
object containing a dictionary, secondary objects that are stored as values in
the dictionary can be opened in inspector by clicking on them. However,
attempting to open the same secondary object if it is stored as a key in the
dictionary will result in nothing happening.
This is fixed by connecting keys to the "object_id_selected" signal the same
way values are connected.
Mrfanta-stick
Pāvels Nadtočajevs
kobewi
StarryWorm
Kevin Lam
Rémi Verschelde
Chaosus
Nintorch
Michael Alexsander
Thaddeus Crews
dugramen
Alexej "Xela" Tušl
Haoyu Qiu
A Thousand Ships