### 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
ret = Vector2(ret.x / 2, ret.y * 2 + ret.x);
					break;
				case TileSet::TILE_LAYOUT_DIAMOND_RIGHT:
					ret = Vector2((ret.x + ret.y) / 2, ret.y - ret.x);
					break;
				case TileSet::TILE_LAYOUT_DIAMOND_DOWN:
					ret = Vector2((ret.x - ret.y) / 2, ret.y + ret.x);
					break;
			}
		} else { 
			switch (tile_set->get_tile_layout()) {
				case TileSet::TILE_LAYOUT_STACKED:
					ret = Vector2(ret.x, ret.y + (Math::posmod(ret.x, 2) == 0 ? 0.0 : 0.5));
					break;
				case TileSet::TILE_LAYOUT_STACKED_OFFSET:
					ret = Vector2(ret.x, ret.y + (Math::posmod(ret.x, 2) == 1 ? 0.0 : 0.5));
					break;
				case TileSet::TILE_LAYOUT_STAIRS_RIGHT:
					ret = Vector2(ret.x * 2 + ret.y, ret.y / 2);
					break;
				case TileSet::TILE_LAYOUT_STAIRS_DOWN:
					ret = Vector2(ret.x, ret.y + ret.x / 2);
					break;
				case TileSet::TILE_LAYOUT_DIAMOND_RIGHT:
					ret = Vector2(ret.x + ret.y, (ret.y - ret.x) / 2);
					break;
				case TileSet::TILE_LAYOUT_DIAMOND_DOWN:
					ret = Vector2(ret.x - ret.y, (ret.y + ret.x) / 2);
					break;
			}