Bounty Pallet: add `approve_bounty_with_curator` call to `bounties` pallet (#5961)

Resolves issue https://github.com/paritytech/polkadot-sdk/issues/5928

Adds `approve_bounty_with_curator` call to the `bounties` pallet to
combine functions of `approve_bounty` and `propose_curator` into one
call. Also adds a new status `ApprovedWithCurator` required to
distinguish if bounty was approved with curator when skipping through
`Funded` status and moving to `CuratorProposed` status.

If `unassign_curator` is called after `approve_bounty_with_curator` the
process will fall back to the old flow of calling `propose_curator`
separately.

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Co-authored-by: DavidK <davidk@parity.io>
Co-authored-by: command-bot <>
Co-authored-by: Ankan <10196091+Ank4n@users.noreply.github.com>