[FEATURE] Add arbitrary extra metadata using the Profile interface

[bdon]

Is your feature request related to a problem? Please describe.
The profile has a few interface methods like name, attribution, version, isOverlay but does not provide a way to add arbitrary other string:string pairs.

Describe the solution you'd like
Another interface method called extraMetadata that is a Map<String,String>

Describe alternatives you've considered

• Using a lower-level interface instead of Profile might give a profile author access to TileArchiveMetadata, but that's more work.
• We can deprecate the individual methods name, version, attribution and instead make all metadata go through one metadata interface method that returns Map<String,String>

Additional context
We should consider how key conflicts between extraMetadata and name, version... as well as with build-time info planetiler:githash and run-time info (osmosis:*) choose which source gets priority.