Backspace doesn't delete selection if selected beyond TextEdit

[KoBeWi]

Godot version

5636903

System information

Windows 10 x64

Issue description

When you select text in TextEdit, particularly from right to left, with cursor finishing beyond the TextEdit, Backspace has no effect:

Steps to reproduce

1. Have TextEdit (Button text in the inspector or script editor)
2. Type any text
3. Select everything by dragging mouse over the text and waaay to the left
4. Press Backspace

Minimal reproduction project

No response

[pfertyk]

I'd like to submit a fix.

The code checked if the beginning of the text was reached (line == 0 and column == 0). If so, it didn't remove the text. This resulted in any selection from right to left (that extended to the beginning of the text) to not work with backspace. The selection didn't have to go beyond the frame of the TextEdit, just to the beginning of the first word (worked both with mouse drag and with Shift + left arrow).

Selecting the text from left to right worked fine, because the caret was placed at the end of the text, not the beginning, so the condition was not met.

I've added another part to the condition, checking if there is a selection available ;)