### 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
}
	}
	
	RBSet<TerrainConstraint> constraints;
	
	for (Vector2i coords : p_coords_array) {
		
		RBSet<TerrainConstraint> added_constraints = _get_terrain_constraints_from_added_pattern(coords, p_terrain_set, p_terrains_pattern);
		for (TerrainConstraint c : added_constraints) {
			c.set_priority(10);
			constraints.insert(c);
		}
	}
	
	for (TerrainConstraint c : _get_terrain_constraints_from_painted_cells_list(p_layer, painted_set, p_terrain_set, p_ignore_empty_terrains)) {
		constraints.insert(c);
	}
	
	output = terrain_fill_constraints(p_layer, can_modify_list, p_terrain_set, constraints);
	return output;
}
void TileMap::set_cells_terrain_connect(int p_layer, TypedArray<Vector2i> p_cells, int p_terrain_set, int p_terrain, bool p_ignore_empty_terrains) {
	ERR_FAIL_COND(!tile_set.is_valid());
	ERR_FAIL_INDEX(p_layer, (int)layers.size());
	ERR_FAIL_INDEX(p_terrain_set, tile_set->get_terrain_sets_count());
	Vector<Vector2i> cells_vector;
	HashSet<Vector2i> painted_set;
	for (int i = 0; i < p_cells.size(); i++) {
		cells_vector.push_back(p_cells[i]);
		painted_set.insert(p_cells[i]);