refactor network tests

[dkijania]

Predecessor of #16415. Extracted mock and tests for transaction pool from transaction_pool.ml and introduced:

• transaction_pool_mock.ml - with all necessary utilities to simulate daemon transaction pool
• transaction_pool_tests.ml - with all existing tests for transaction pool

A few words of explanation about current split of code between mock and tests. We need to place verifier under test_module part as it fails otherwise with error:

File "src/lib/network_pool/test/dune", line 2, characters 8-12:
2 |  (names main)
            ^^^^
{"timestamp":"2025-01-07 17:24:03.028851Z","level":"Info","source":{"module":"Verifier__Prod","location":"File \"src/lib/verifier/prod.ml\", line 421, characters 4-15"},"message":"Starting a new verifier process","metadata":{}}
Uncaught exception:
  
  (monitor.ml.Error
   "You must initialize this process to run as a master before calling [spawn]. Either use a top-level [start_app] call or use the [Expert] module."
   ("Raised at Base__Error.raise in file \"src/error.ml\" (inlined), line 8, characters 14-30"
    "Called from Base__Or_error.ok_exn in file \"src/or_error.ml\", line 84, characters 17-32"
    "Called from Async_kernel__Deferred1.M.map.(fun) in file \"src/deferred1.ml\", line 17, characters 40-45"
    "Called from Async_kernel__Job_queue.run_job in file \"src/job_queue.ml\" (inlined), line 128, characters 2-5"
    "Called from Async_kernel__Job_queue.run_jobs in file \"src/job_queue.ml\", line 169, characters 6-47"
    "Caught by monitor Verifier RPC worker at file \"src/lib/verifier/prod.ml\", line 435, characters 29-29"))

Raised at Base__Result.ok_exn in file "src/result.ml" (inlined), line 201, characters 17-26
Called from Async_unix__Thread_safe.block_on_async_exn in file "src/thread_safe.ml", line 132, characters 29-63
Called from Async_unix__Thread_safe.block_on_async_exn in file "src/thread_safe.ml" (inlined), line 181, characters 27-54
Called from Network_pool__Test_utils.verifier in file "src/lib/network_pool/test_utils.ml", line 53, characters 6-299

That's why mock accepts all parameters like genesis_constants and constraint_constants

[dkijania]

!ci-build-me

[dkijania]

!ci-build-me

[dkijania]

!ci-nightly-me

[dkijania]

Nightly: https://buildkite.com/o-1-labs-2/mina-end-to-end-nightlies/builds/3141

[georgeee]

I didn't review in full all of the mock internals, but I assume they were just copy-pasted with adding some additional functional parameters. Changes to tests look great!

[georgeee]

Suggested change

	Verifier.For_tests.default ~logger ~proof_level ~conf_dir:None
	Verifier.For_tests.default ~logger ~proof_level:Full ~conf_dir:None

And let's remove declaration verifier_full below in this file

[dkijania]

!ci-build-me