test: Run feature_cltv with MiniWallet

Summary:
Backport of core#21754.

Because we enforce push only in script sigs this code has been heavily adapted, it's more inpired by than an actual backport.

Depends on D12435.

Test Plan:
With and without the wallet:

./test/functional/test_runner.py feature_cltv
ninja check-functional

Reviewers: #bitcoin_abc, sdulfari

Reviewed By: #bitcoin_abc, sdulfari

Differential Revision: https://reviews.bitcoinabc.org/D12436