Nuke `NoteIntreface::compute_note_hash_and_nullifier_without_context(...)`

[benesjan]

Now that we have UnconstrainedContext it should be possible to nuke compute_note_hash_and_nullifier_without_context from note interface and just have compute_note_hash_and_nullifier. Note that it will be necessary to come up with a ContextTrait:

- fn compute_note_hash_and_nullifier(self, context: &mut PrivateContext) -> (Field, Field);
+ fn compute_note_hash_and_nullifier(self, context: &mut ContextTrait) -> (Field, Field);

Note: Wait for this slack discussion to resolve before tackling.

[benesjan]

no longer relevant