Enforce Trampoline constraints

We add a `check_trampoline_constraints` similar to
`check_blinded_path_constraints` that compares the Trampoline onion's amount
and CLTV values to the limitations imposed by the outer onion.

Also, we add and modify the following tests:
- Modified the unblinded receive to validate when receiving amount less than
expected.
- Modified test with wrong CLTV parameters that now fails with new enforcement
of CLTV limits.
- Add unblinded and blinded receive tests that forces trampoline onion's CLTV to
be greater than the outer onion packet.

Note that there are some TODOs to be fixed in following commits as we need
the full trampoline forwarding feature to effectively test all cases.

Co-authored-by: Arik Sosman <[email protected]>

Author: a-mpch