User defined default project directory for Project Manager

[Cautami]

This PR aims to allow the user to set the default location of where new projects are created.

Screencast_20251014_011447.webm

I've marked it as draft as it needs testing, and I'm unsure if this is the right way of implementing it.

All references to filesystem/directories/default_project_path have been changed to ../user_defined_project_path.
default_project_path is now always the Godot default location, this is so the user can delete their custom directory and see a placeholder of where the original directory was.

user_defined_project_path is set to the same value as default_project_path on creation, but can be changed via the settings menu.
In theory, this shouldn't cause any loss of functionality for users used to this, and should only serve to improve the experience.

I still need to add translations (or well, the support for such) and change the naming(?), perhaps calling the user_defined option the "default" in the settings menu is misleading? Even though it is true...
Or perhaps call user_defined -> default, and call default... something else I guess?

I'm also toying with the idea of adding a reset button that resets the path to the true default, but given no other option has this functionality I'm unsure if it'd fit.

[Cautami]

I've added the user_defined_path member to the EditorSettings.xml and updated the default_project_path member to more accurately depict what the default_project_path is now.
I'm unsure of how to handle the actual translations of Godot however 😅

[Meorge]

Related: godotengine/godot-proposals#1312 and godotengine/godot-proposals#11224

[Cautami]

Oh I should've checked to see existing PRs I suppose, sorry!
I think yours has superior functionality, so I'll close this in favor of that (#99608)

[Meorge]

No worries! 😄 It's happened to me a few times too, that I've written proposals, issues, or PRs only to find out there was a similar one buried in the repository somewhere.

It sounds to me like the one I did was more minimal (didn't have a user_defined_project_path or similar), otherwise I think they're pretty similar. What was the reasoning for the user_defined_project_path as opposed to reusing the existing default_project_path? Perhaps that would make your PR a better alternative?

[Cautami]

I decided to create user_defined because I wanted to keep Godot's default path always accessible, mostly for the placeholder text if the user were to erase the path, or for a reset button to help encourage experimentation like a lot of Godot's properties enable.
I was also partially worried overriding the behavior would have negative consequences if something out there relied on it, for whatever reason. Didn't want to stomp on anyone's toes.