Clear out delegationRequest

[allinox]

With the use of rtkQuery, the contents of this file can be moved to other places for better state handling and simplification of react code.

Things to consider:

• Mapping logic can be moved to BFF
• post of api can be done in batch, if BFF handles logic for that
• If post of api is to be done as an rtkQuery mutation, the issue of fetching these results on the new page must be handled
  • Cashing?
  • Posting on receipt page instead of on summary page?
  • Storing in state? (Keep as dispatch?)

To do:

• [ ] Move postApiDelgations dispatch function to rtkQuery in apiDelegationApi (if suitable)
  • [ ] If not, move to common apiDelegationSlice
• [ ] Move batch post logic to BFF (return list of successfull and not successfull lists from delegation endpoint)
• [ ] Delete delegableRequestSlice