### Godot version

v4.0.beta11.official [91713ced8]

### System information

MX Linux 21

### Issue description

In Godot 3, TileMap had methods get_used_cells() and get_used_cells_by_id(). Godot 4's TileMap only has get_used_cells() and is missing get_used_cells_by_id().

get_used_cells_by_id() is highly useful in multiple cases, for example when trying to get all cells that are of road type, to randomly spawn a car.

Re-implementing get_used_cells_by_id() should be simple. The method could simply call get_used_cells(), and ignore all cells that are of the wrong ID.

### Steps to reproduce

N/A

### Minimal reproduction project

N/A
} else {
					output = Vector2i(output.x / 2, output.x + output.y * 2);
				}
			}
			break;
		case TileSet::TILE_LAYOUT_DIAMOND_RIGHT:
		case TileSet::TILE_LAYOUT_DIAMOND_DOWN:
			if ((p_from_layout == TileSet::TILE_LAYOUT_DIAMOND_RIGHT) ^ (p_offset_axis == TileSet::TILE_OFFSET_AXIS_VERTICAL)) {
				if ((output.x + output.y) < 0 && (output.x - output.y) % 2) {
					output = Vector2i((output.x + output.y) / 2 - 1, output.y - output.x);
				} else {
					output = Vector2i((output.x + output.y) / 2, -output.x + output.y);
				}
			} else {
				if ((output.x - output.y) < 0 && (output.x + output.y) % 2) {
					output = Vector2i((output.x - output.y) / 2 - 1, output.x + output.y);
				} else {
					output = Vector2i((output.x - output.y) / 2, output.x + output.y);
				}
			}
			break;
	}
	switch (p_to_layout) {
		case TileSet::TILE_LAYOUT_STACKED:
			break;
		case TileSet::TILE_LAYOUT_STACKED_OFFSET:
			if (output.y % 2) {
				output.x += 1;
			}
			break;