### 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
if (tile_offset_axis == TileSet::TILE_OFFSET_AXIS_HORIZONTAL) {
		if (tile_shape == TileSet::TILE_SHAPE_ISOMETRIC) {
			overlapping_ratio = 0.5;
		} else if (tile_shape == TileSet::TILE_SHAPE_HEXAGON) {
			overlapping_ratio = 0.75;
		}
		ret.y /= overlapping_ratio;
	} else { 
		if (tile_shape == TileSet::TILE_SHAPE_ISOMETRIC) {
			overlapping_ratio = 0.5;
		} else if (tile_shape == TileSet::TILE_SHAPE_HEXAGON) {
			overlapping_ratio = 0.75;
		}
		ret.x /= overlapping_ratio;
	}
	
	if (tile_shape == TileSet::TILE_SHAPE_HALF_OFFSET_SQUARE || tile_shape == TileSet::TILE_SHAPE_HEXAGON || tile_shape == TileSet::TILE_SHAPE_ISOMETRIC) {
		
		
		if (tile_offset_axis == TileSet::TILE_OFFSET_AXIS_HORIZONTAL) {
			
			Vector2 raw_pos = ret;
			if (Math::posmod(Math::floor(ret.y), 2) ^ (tile_layout == TileSet::TILE_LAYOUT_STACKED_OFFSET)) {
				ret = Vector2(Math::floor(ret.x + 0.5) - 0.5, Math::floor(ret.y));
			} else {
				ret = ret.floor();
			}
			
			Vector2 in_tile_pos = raw_pos - ret;
			bool in_top_left_triangle = (in_tile_pos - Vector2(0.5, 0.0)).cross(Vector2(-0.5, 1.0 / overlapping_ratio - 1)) <= 0;