Update demos to use TileMapLayer instead of the deprecated TileMap

[TheLoneInitiate]

Please update this to show how it is used with the new TileMapLayer

[Calinou]

#1133 updated the Dynamic TileMap Layers demo, but many other demos remain to be updated.

Up-to-date projects:

~/Documents/Git/godotengine/godot-demo-projects master*
❯ rg 'type="TileMapLayer"'
networking/multiplayer_bomber/world.tscn
11:[node name="Layer0" type="TileMapLayer" parent="."]

2d/dynamic_tilemap_layers/world.tscn
24:[node name="Ground" type="TileMapLayer" parent="."]
29:[node name="Secret" type="TileMapLayer" parent="."]

2d/platformer/level/level.tscn
69:[node name="TileMapLayer" type="TileMapLayer" parent="."]
~/Documents/Git/godotengine/godot-demo-projects master*

Outdated projects:

❯ rg 'type="TileMap"'     
2d/navigation_astar/game.tscn
31:[node name="TileMap" type="TileMap" parent="."]

2d/kinematic_character/world.tscn
125:[node name="TileMap" type="TileMap" parent="."]

2d/skeleton/level.tscn
12:[node name="TileMap" type="TileMap" parent="."]

2d/role_playing_game/grid_movement/exploration.tscn
33:[node name="Ground" type="TileMap" parent="."]
40:[node name="Pathways" type="TileMap" parent="."]
627:[node name="Grid Walkable Floor" type="TileMap" parent="."]
633:[node name="Grid" type="TileMap" parent="." node_paths=PackedStringArray("dialogue_ui")]

2d/isometric/dungeon.tscn
424:[node name="Floor" type="TileMap" parent="."]
530:[node name="Walls" type="TileMap" parent="."]
795:[node name="HighWalls" type="TileMap" parent="."]
803:[node name="HighWalls2" type="TileMap" parent="."]

2d/hexagonal_map/map.tscn
8:[node name="TileMap" type="TileMap" parent="."]

2d/physics_platformer/stage.tscn
132:[node name="TileMap" type="TileMap" parent="."]

2d/physics_tests/tests/functional/test_character_tilemap.tscn
135:[node name="TileMap" type="TileMap" parent="."]