test: Add generate* calls to test framework

Summary:
Backport of core#22741.

Depends on D12475.

Note that only a few calls to generate* are replaced in this PR, and the selection seems arbitrary. The other callsites will be replaced in another backport.

Test Plan:

ninja check-extended

Reviewers: #bitcoin_abc, PiRK

Reviewed By: #bitcoin_abc, PiRK

Subscribers: PiRK

Differential Revision: https://reviews.bitcoinabc.org/D12476