feat: pull in the core stacks-bench tooling into contrib/ + minor supporting stackslib and clarity tweaks

[cylewitruk-stacks]

Pulls in the core stacks-bench binary/tooling into the contrab/ dir.

TODO: Will fill in more information here tomorrow.

[coveralls]

Coverage Report for CI Build 27311369692

Coverage increased (+0.2%) to 85.863%

Details

• Coverage increased (+0.2%) from the base build.
• Patch coverage: 10 uncovered changes across 1 file (2 of 12 lines covered, 16.67%).
• 7331 coverage regressions across 124 files.

Uncovered Changes

File	Changed	Covered	%
stackslib/src/chainstate/stacks/db/mod.rs	10	0	0.0%
Total (3 files)	12	2	16.67%

Coverage Regressions

7331 previously-covered lines in 124 files lost coverage.

Top 10 Files by Coverage Loss	Lines Losing Coverage	Coverage
stackslib/src/config/mod.rs	376	68.96%
stackslib/src/net/mod.rs	310	78.12%
stackslib/src/chainstate/stacks/index/storage.rs	277	82.41%
clarity/src/vm/database/clarity_db.rs	268	82.11%
stackslib/src/chainstate/stacks/miner.rs	253	83.4%
stackslib/src/chainstate/stacks/db/transactions.rs	222	97.16%
stackslib/src/net/inv/epoch2x.rs	222	79.44%
stackslib/src/chainstate/nakamoto/mod.rs	208	84.66%
stackslib/src/net/chat.rs	201	92.97%
stackslib/src/chainstate/stacks/db/mod.rs	198	85.81%

---

Coverage Stats

Relevant Lines:	224991
Covered Lines:	193184
Line Coverage:	85.86%
Coverage Strength:	20617180.48 hits per line

---

💛 - Coveralls