test(dursto): add integration test for database for roundtrip of proofs

[NSant215]

Closes RV-1004.
Related to RV-985.

What

Adds a multi-step roundtrip test to the Database module (excluding copying and moving).
Converges test architecture with integration_test.rs and merkle_layer roundtrip tests, as they all use similar enums.

Why

Add confidence in multi-step proofs working.

How

create a proof_test_utils module with helpers for running operations on the database vs the merkle layer.

Tasks for the Author

• Link all Linear issues related to this MR using magic words (e.g. part of, relates to, closes).
• Eliminate dead code and other spurious artefacts introduced in your changes.
• Document new public functions, methods and types.
• Make sure the documentation for updated functions, methods, and types is correct.
• Add tests for bugs that have been fixed.
• Explain changes to regression test captures when applicable.
• Write commit messages in agreement with our guidelines.
• Self-review your changes to ensure they are high-quality.
• Complete all of the above before assigning this MR to reviewers.

[codecov]

Codecov Report

❌ Patch coverage is 97.22222% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 90.14%. Comparing base (cb94308) to head (1c9567e).

Files with missing lines	Patch %	Lines
durable-storage/src/proof_test_utils.rs	96.36%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1064      +/-   ##
==========================================
- Coverage   90.16%   90.14%   -0.02%     
==========================================
  Files         130      131       +1     
  Lines       27969    28010      +41     
  Branches    27969    28010      +41     
==========================================
+ Hits        25217    25250      +33     
- Misses       2004     2011       +7     
- Partials      748      749       +1     

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[github-actions]

Benchmark results for revision f1ca0fc:

Metric	Duration	TPS
Mean	1.517784885s	26.355
Worst	1.532514766s	26.101
Best	1.507442154s	26.535
Standard Deviation	±5.832602ms	±0.101

Full results

Run	Transfers	Duration	TPS
1	40	1.519048224s	26.332
2	40	1.521227018s	26.295
3	40	1.513263606s	26.433
4	40	1.50913651s	26.505
5	40	1.525102579s	26.228
6	40	1.514706801s	26.408
7	40	1.532514766s	26.101
8	40	1.521266907s	26.294
9	40	1.523398575s	26.257
10	40	1.51609731s	26.384
11	40	1.520835637s	26.301
12	40	1.525287681s	26.225
13	40	1.517514453s	26.359
14	40	1.515049905s	26.402
15	40	1.513210197s	26.434
16	40	1.51736205s	26.362
17	40	1.511940895s	26.456
18	40	1.515056805s	26.402
19	40	1.516235619s	26.381
20	40	1.507442154s	26.535

Compare the results above with those for the default branch.

[NSant215]

waiting on PR #1065 to avoid overlap work