Add support for multi-value input in tools explorer

The code looks good here, one thing that we are not using now and I'm not sure how it actually makes sense is that the Context Definition has a parameter multiple that we actually do not care about right now - I can't really think of a place where you set an list (which becomes array) where you would only want to pick one - you would rather do string or int with enums then.

I is controlled via anyOf/oneOf in the providers function calling, I'm not sure if we need some future issue to map to that when multiple false is specifically set on a list/map.

Btw - this MR is still in draft, so can't merge.

I've resolved the merge conflicts on this MR.

Getting merged, thank you both.