### 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
Vector2 in_tile_pos = raw_pos - ret;
			bool in_top_left_triangle = (in_tile_pos - Vector2(0.0, 0.5)).cross(Vector2(1.0 / overlapping_ratio - 1, -0.5)) > 0;
			bool in_bottom_left_triangle = (in_tile_pos - Vector2(0.0, 0.5)).cross(Vector2(1.0 / overlapping_ratio - 1, 0.5)) <= 0;
			switch (tile_layout) {
				case TileSet::TILE_LAYOUT_STACKED:
					ret = ret.floor();
					if (in_top_left_triangle) {
						ret += Vector2i(-1, Math::posmod(Math::floor(ret.x), 2) ? 0 : -1);
					} else if (in_bottom_left_triangle) {
						ret += Vector2i(-1, Math::posmod(Math::floor(ret.x), 2) ? 1 : 0);
					}
					break;
				case TileSet::TILE_LAYOUT_STACKED_OFFSET:
					ret = ret.floor();
					if (in_top_left_triangle) {
						ret += Vector2i(-1, Math::posmod(Math::floor(ret.x), 2) ? -1 : 0);
					} else if (in_bottom_left_triangle) {
						ret += Vector2i(-1, Math::posmod(Math::floor(ret.x), 2) ? 0 : 1);
					}
					break;
				case TileSet::TILE_LAYOUT_STAIRS_RIGHT:
					ret = Vector2(ret.x / 2 - ret.y, ret.y * 2).floor();
					if (in_top_left_triangle) {
						ret += Vector2i(0, -1);
					} else if (in_bottom_left_triangle) {
						ret += Vector2i(-1, 1);
					}
					break;
				case TileSet::TILE_LAYOUT_STAIRS_DOWN:
					ret = Vector2(ret.x, ret.y - ret.x / 2).floor();