### Godot version

4.0 stable

### System information

Manjaro Linux, kernel 6.1.1-1-MANJARO, AMD Ryzen 5 3600, AMD RX 580

### Issue description

The `wrap_mode` property of the `TextEdit` node doesn't seem to really do anything. Setting it to `LINE_WRAPPING_BOUNDARY` simply means that there won't be an horizontal scrollbar if the text overshoots the boundary, instead of actually forcing the text to the next line so that it stays visible.

### Steps to reproduce

Create a TextEdit node and set its `wrap_mode` property to `LINE_WRAPPING_BOUNDARY`

### Minimal reproduction project

[WrapBugDemo.zip](https://github.com/godotengine/godot/files/10875969/WrapBugDemo.zip)

p_new_line--;
			caret_wrap_index = get_line_wrap_count(p_new_line);
		} else {
			caret_wrap_index--;
		}
	}
	
	if (p_new_line < 0) {
		p_new_line = 0;
	}
	if (p_new_line >= text.size()) {
		p_new_line = text.size() - 1;
	}
	p_new_column = _get_char_pos_for_line(p_last_fit_x, p_new_line, caret_wrap_index);
	if (p_new_column != 0 && get_line_wrapping_mode() != LineWrappingMode::LINE_WRAPPING_NONE && caret_wrap_index < get_line_wrap_count(p_new_line)) {
		Vector<String> rows = get_line_wrapped_text(p_new_line);
		int row_end_col = 0;
		for (int i = 0; i < caret_wrap_index + 1; i++) {
			row_end_col += rows[i].length();
		}
		if (p_new_column >= row_end_col) {
			p_new_column -= 1;
		}
	}
}
void TextEdit::_update_placeholder() {
	if (theme_cache.font.is_null() || theme_cache.font_size <= 0) {
		return; 
	}