Nakamoto-Node: Support for interim block mining

[kantai]

Description

This PR adds support to the nakamoto node for interim block mining (i.e., blocks within the current tenure) with a configurable wait time between such blocks. This PR also refactors the chainstate::nakamoto::miner module to match the actual usage of the miner interfaces, and moving the TestPeer specific method out into TestPeer itself.

This adds a new nakamoto_integration test which mines 10 nakamoto tenures, each with 2 blocks in the tenure.

[codecov]

Codecov Report

Attention: 34 lines in your changes are missing coverage. Please review.

Comparison is base (8cffc38) 85.08% compared to head (3cef3b4) 65.52%.

Files	Patch %	Lines
stackslib/src/chainstate/nakamoto/tests/node.rs	71.18%	17 Missing ⚠️
testnet/stacks-node/src/nakamoto_node/miner.rs	80.59%	13 Missing ⚠️
stackslib/src/chainstate/nakamoto/miner.rs	95.91%	2 Missing ⚠️
...net/stacks-node/src/tests/nakamoto_integrations.rs	98.67%	2 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##             next    #4187       +/-   ##
===========================================
- Coverage   85.08%   65.52%   -19.57%     
===========================================
  Files         429      429               
  Lines      302009   302067       +58     
===========================================
- Hits       256976   197933    -59043     
- Misses      45033   104134    +59101     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[jcnelson]

LGTM, provided that all tests pass. Thanks for the NakamotoBlockBuilder cleanup!

[kantai]

The code coverage drop seems to be due to tests which aren't run on PRs, but are run on the base branch (e.g., the epoch tests). The patch coverage is 90%.