PB-1550: removed obsolete preprocessor

[hansmannj]

Since the API now handles the geo+json content type issue, we should remove the preprocessor from the browser's config

[sami-nouidri-swisstopo]

I tried before yesterday's deployment and today again, but it seems without the hook the search just doesn't show up :

[ltshb]

I don't understand here, @sami-nouidri-swisstopo added this very recently and now you remove it ? Did you try it does it work without it ? But now we also downgraded STAC to v1.37...

[hansmannj]

Since we adapted the API so that the search endpoints reply with a geo+json if this is explicitly requested via the accept header, I thought, that would make the preprocessing obsolete, but obviously it doesn't.
Maybe I'll use this PR to add a comment on the preprocessor, so that we know someday in future, why we have it and when we can remove it.