### 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
set_global_transform(last_valid_transform);
				set_notify_local_transform(true);
			}
		} break;
	}
}
void TileMap::_physics_update_dirty_quadrants(SelfList<TileMapQuadrant>::List &r_dirty_quadrant_list) {
	ERR_FAIL_COND(!is_inside_tree());
	ERR_FAIL_COND(!tile_set.is_valid());
	Transform2D gl_transform = get_global_transform();
	last_valid_transform = gl_transform;
	new_transform = gl_transform;
	PhysicsServer2D *ps = PhysicsServer2D::get_singleton();
	RID space = get_world_2d()->get_space();
	SelfList<TileMapQuadrant> *q_list_element = r_dirty_quadrant_list.first();
	while (q_list_element) {
		TileMapQuadrant &q = *q_list_element->self();
		
		for (RID body : q.bodies) {
			bodies_coords.erase(body);
			ps->free(body);
		}
		q.bodies.clear();
		
		for (const Vector2i &E_cell : q.cells) {
			TileMapCell c = get_cell(q.layer, E_cell, true);
			TileSetSource *source;
			if (tile_set->has_source(c.source_id)) {
				source = *tile_set->get_source(c.source_id);
				if (!source->has_tile(c.get_atlas_coords()) || !source->has_alternative_tile(c.get_atlas_coords(), c.alternative_tile)) {