Provide redirect and token Firebase functions to allow OSM log in for MapSwipe web

[ofr1tz]

MapSwipe app allows for authentication through OpenStreetMap OAuth2 for a while already, the MapSwipe web application lacks this feature so far.

Two different Firebase functions (redirect and token) are currently provided to enable OSM authentication for the smartphone app. This PR provides the additional two respective Firebase functions redirectweb and tokenweb to allow for OSM authentication through the web app.

The additional functions work pretty much the same as the existing ones, but use a different OSM OAuth client with a different redirect link. This is necessary, as the redirect URL has to be the same as the one defined for the OSM OAuth client.

In addition to that, this PR includes a fix to an existing bug to avoid that OSM authenticated profiles are overwritten on Firebase RTDB with each new log in.

Prerequisites

This introduces four new .env variables that need to be set:

• OSM_OAUTH_REDIRECT_URI_WEB: The URI to redirect to after authorizing the client with OSM. Should be https://auth.mapswipe.org/tokenweb (https://dev-auth.mapswipe.org/tokenweb for the dev instance)
• OSM_OAUTH_CLIENT_ID_WEB: The client ID of the client registered with OSM OAuth2
• OSM_OAUTH_CLIENT_SECRET_WEB: The client secret of the client registered with OSM OAuth2. Note that the client for MapSwipe dev instance is not registered on openstreetmap.org, but on OSM dev instance (master.apis.dev.openstreetmap.org/)
• OSM_OAUTH_APP_LOGIN_LINK_WEB: The URI to redirect to from tokenweb. Should be https://web.mapswipe.org/#/osm-callback (https://web.mapswipe.org/dev/#/osm-callback for MapSwipe dev instance)

Deployment

To properly deploy the updated functions on the server, make sure to remove the firebase_deploy image first:

docker rmi python-mapswipe-workers-firebase_deploy
make update_firebase_functions_and_db_rules

Test

• This PR is currently deployed on MapSwipe dev instance with OSM_OAUTH_APP_LOGIN_LINK_WEB='http://localhost:5173/#/osm-callback' for testing purposes
• 17 enhancement add the ability to sign in using an osm account mapswipe-web#67 implements OSM authentication on the MapSwipe web client

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Fixes #1030