feat: Adds --update-cache flag to 'server'.

[cskau]

TileServerHandlerhas an attribute, update_cache which is hardcoded to False.

map-machine/map_machine/slippy/server.py

Line 22 in 825eb34

update_cache: bool = False

This prevents the map-machine server command from serving tiles that aren't already in the cache:

map-machine/map_machine/slippy/server.py

Lines 48 to 60 in 825eb34

	if self.update_cache:
	if not png_path.exists():
	if not svg_path.exists():
	tile.draw(
	tile_path,
	self.cache,
	MapConfiguration(zoom_level=zoom_level),
	)
	with svg_path.open(encoding="utf-8") as input_file:
	cairosvg.svg2png(
	file_obj=input_file, write_to=str(png_path)
	)
	logging.info(f"SVG file is rasterized to {png_path}.")

This PR exposes update_cache as a command line flag.