[Feature Request] add Paikka support

[dgraf-gh]

After writing our own reverse geocoder we should add support for it also into reitti.
Benefits of having this is that it is custom made for reitti regarding the responses and the poi which are indexed.

• For this we will add a type switch to the current geocoders and priority to the geocoders
• photon should still be supported but we will drop it from the compose file like we do it in the minimal docker compose file
• photon will be dropped as the custom geocoder and will be added as service into the table
• there will be a default geocoder for paikka added but this is also just an entry in the table
• we will drop all the custom photon handling
• logic stays the same, we will first try paikka, then one of the configured ones

Logic in selecting a geocoder is:

• sort them by priority into buckets
• every geocoder will be queried randomly in a bucket
• if the queried one, does not return anything or it cant be understood, try the next one in the bucket
• if none returns data inside a bucket, go to the next bucket and try again