Fix TextEdit visible line count when setting text

[kitbdev]

• fixes total_visible_line_count decreases indefinitely when setting TextEdit's text with boundary wrap mode #102279
• fixes TextEdit with line wrapping becomes unusable when repeatedly setting text via code. #102211

remove_range actually removes from p_from_line + 1 to p_to_line, it seems weird, but it is to preserve gutters on the first line I think. The line content will be replaced afterwards anyway.

The total_visible_line_count should now be in sync with the actual text that is removed, so the future call to invalidate_text will calculate the change correctly.

The for loop should function the same but be more clear.
remove_range is only called from _base_remove_text which handles validation of the arguments so it isn't needed here. The max and min functions never do anything.

[tracefree]

Thanks for the quick fix! I can confirm everything works as expected now in my MRP attached to #102279, also when I swap the long and short line.