test: Add RegTestingSetup to setup_common #17228

The default chain for TestingSetup is the main chain. However, any test that wants to mine blocks on demand needs to switch to regtest. This is done manually and in-line right now.

Fix that by creating an explicit RegTestingSetup and use it where appropriate.

Also, add a move-only commit to move ComputeFilter into the newly created unit test library.

Both commits are part of #15845, but split up because they are useful on their own.

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Conflicts

Reviewers, this pull request conflicts with the following ones:

• #16540 (test: Add ASSERT_DEBUG_LOG to unit test framework by MarcoFalke)

If you consider this pull request important, please also help to review the conflicting pull requests. Ideally, start with the one that should be merged first.

Concept ACK

Rebased

Anything left to do here?

ACK fa0a731d007a8e76d2740a2e6ead2289de77e475 -- diff looks correct