Request for Improved LineEdit Focus Handling: Allow Releasing Focus by Clicking Empty Space

[Dx-hualuo]

When using the LineEdit node in Godot, I noticed an unintuitive focus behavior:

1. After clicking a LineEdit and starting input, it gains focus as expected.
2. If I click on an empty area of the UI (e.g., a blank part of a Panel or the root container) while editing, the LineEdit retains focus instead of releasing it.
3. To release focus, I must click another interactive control (e.g., a Button or another LineEdit), which disrupts workflow efficiency.

Expected Behavior:
Clicking non-interactive UI regions (e.g., transparent areas of a Panel, ColorRect, or background containers) should trigger focus_exited() for the focused LineEdit, aligning with common UI/UX conventions in other applications.

Proposed Solution
Add an optional focus_lost_on_click_outside property to LineEdit (default: true) to automatically release focus when clicking unrelated UI areas.

[Calinou]

I agree clicking outside should release focus for both LineEdit and TextEdit. This behavior is seen in other applications like web browsers after all (example).