Make Context Input requirement checks syntactic

[PhilippGackstatter]

Make Context Input requirement checks syntactic.

For any feature or unlock condition that requires a Commitment, Block Issuance Credit or Reward Input we want to check syntactically whether that requirement is fulfilled. Currently, this is done at the semantic validation stage.

We can implement that as: func OutputsSyntacticalContextInputs() ElementValidationFunc[Output].

Note that we do not have to implement the check that a BIC or Reward Input requires a Commitment Input, since that is already checked in ContextInputsCommitmentInputRequirement.

Finally, also update the TIPs accordingly to move the check from the semantic to the syntactic section.