Add documentation tooltips to the Debugger > Monitors editor bottom panel

[Calinou]

• Related to Add tooltips to font import window #9585.

Describe the project you are working on

The Godot editor 🙂

Describe the problem or limitation you are having in your project

The Debugger > Monitors bottom panel of the editor currently doesn't display the documentation when hovering each performance monitor:

Compare this with the inspector, Import dock or Export dialog where such tooltips are displayed:

Describe the feature / enhancement and how it helps to overcome the problem or limitation

Add documentation tooltips to the Debugger > Monitors editor bottom panel.

Describe how your proposal will work, with code, pseudo-code, mock-ups, and/or diagrams

We already have descriptions for all built-in performance monitors in the Performance class reference. Since the monitors use a Tree to display the list of options you can check, the implementation would look similar to the one used for editor Import options in godotengine/godot#49524.

For custom performance monitors (which could be tackled in a separate PR), this would likely involve an additional optional parameter at the end of Performance.add_custom_monitor() (or perhaps a separate method you call after registering the custom monitor).

If this enhancement will not be used often, can it be worked around with a few lines of script?

No.

Is there a reason why this should be core and not an add-on in the asset library?

This is about improving editor usability, helping users understand what each of the performance monitors is useful for.