Element Desktop (Electron) loads the location-sharing map style from a
`vector://vector` origin, so fetching map_style.json from the Element
domain is a cross-origin request. Without an Access-Control-Allow-Origin
header, the request is blocked and maps fail to load with "This homeserver
is not configured correctly to display maps".

Add a dedicated Traefik router for map_style.json that attaches an
Access-Control-Allow-Origin header (configurable via
matrix_client_element_location_sharing_map_style_access_control_allow_origin,
defaulting to `*`). It is only defined when location sharing is enabled.

Fixes #2291

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

Most of these files were defining a service, usually toward the end.
These lines have been moved upward.

Some components (mautrix-signal, mautrix-gmessages, etc.) were defining
a service conditionally (only if metrics are exposed, etc). This was
causing issues like these in the Traefik logs:

> level=error msg="service \"matrix-mautrix-twitter\" error: port is missing" providerName=docker container=matrix-mautrix-twitter-..

This may proof useful to someone in the future.

Previously, it had to go through matrix-nginx-proxy.
It's exposed to Traefik directly via container labels now