Add size check to prevent popup bigger than the screen itself

[sepTN]

Add size check to prevent popup bigger than the screen itself.

Fix #78594 however I'm not sure if this is the correct way to do it. Maybe if there's someone who can point me in the right direction.

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First, as per the issue #78594 to cause the freeze, have a ridiculous dialog_bounds value in your:
.godot/editor/project_metadata.cfg

[editor_metadata]

executable_path="C:/godok/bin/godot.windows.editor.x86_64.exe"

[debug_options]

run_live_debug=true
run_reload_scripts=true

[recent_files]

scenes=["res://node_2d.tscn"]

[linked_properties]

Node2D:scale=true

[dialog_bounds]

project_settings=Rect2(55, 55, 99999, 99999)

Second, open your Project Settings.

Before (without this pr)

• The Godot Engine will freeze when you try to open Project Settings
  

After (with this pr applied)

• The editor will not spawn popup bigger than the user's screen, no more freeze.
• The window might be off for a bit, but at least now the user can drag it back again and resize it.
  

[Sauermann]

While I haven't tested the PR, the changes seem to solve the linked issue and I don't see any obvious problems with the implementation.

[sepTN]

Thanks! I'll git squash to a single commit in a bit.

[akien-mga]

Thanks!