feature(mining): Enable mining RPCs by default in production builds

[teor2345]

Post-Merge TODOs

• Describe this newly stabilised feature in the CHANGELOG
• Arborist announcement
• Forum update

Motivation

We want to enable mining by default in production builds.

Close #7361
Depends-On: #7744

Solution

• Enable the feature by default
• Update the documentation to remove custom builds and docker images to enable the feature
• Update the README to point to the Docker mining instructions
  • Consistently use ZF funding stream addresses in examples

Testing

• Always set the miner address in tests based on the network

This is a very verbose change, but all it does is pass the network from all the tests down to the base test config method, then set the miner address for mainnet or testnet there.

Review

This is a pretty straightforward change. It doesn't matter which release it goes in.

I'd like extra documentation cleanups to go in another PR or ticket, that's what we're doing with test cleanups.

Reviewer Checklist

• Will the PR name make sense to users?
  • Does it need extra CHANGELOG info? (new features, breaking changes, large changes)
• Are the PR labels correct?
• Does the code do what the ticket and PR says?
  • Does it change concurrent code, unsafe code, or consensus rules?
• How do you know it works? Does it have tests?

Follow Up Work

These follow-up changes will be made in separate PRs:

• Remove extra tests for getblocktemplate-rpcs feature #7362
• any other documentation changes
• any other cleanups

[teor2345]

Failed due to #7744, I restarted CI.

[teor2345]

It seems like the fix in PR #7744 might be needed for CI to pass reliably on this PR.

[arya2]

Looks good, may need a rebase.