Account for nested map params (#277)

[agonzat]

Fixes how mapped params are handled so that nested params within map fields are also accounted for when generating the update/declaration blocks.

E.g.:

example:
  keys:
    type: string_array

  key_structs:
    __map_keys:
      worked_fine:
        type: int
      nested:
        didnt_work: # This
          type: int

Still if multiple maps are stacked they need to be contiguous (same as before).

Fixes #277 .

[diegoferigo-rai]

I'm running into the same issue, and I can confirm that using the branch from this PR fixes it. Is there anything we can do to speed up the merge and get a patch release tagged?

cc @christophfroehlich @pac48

[christophfroehlich]

Can you please make a formal approval in the github UI here? ;) I could merge this, but I have no rights to do releases.