Eradicate mediated connection from issuance and presentation integration tests, part 2

[mirgee]

Continuation of #967.

• Completely removes usage of MediatedConnection and agency_client from any and all integration tests.
• Removes legacy agency tests.
• MySQL tests are preserved, where keypair generation is used to test MySQL connection.
• Redundant integration_tests and tests modules were removed.
• Alice and Faber were significantly pruned, where the plan is to replace them with a singular test agent impl.

[Patrik-Stas]

amazing again :-) Huge burden droped off once more

[codecov-commenter]

Codecov Report

Merging #974 (134c147) into main (3b77552) will decrease coverage by 5.39%.
The diff coverage is 78.87%.

@@            Coverage Diff             @@
##             main     #974      +/-   ##
==========================================
- Coverage   35.14%   29.76%   -5.39%     
==========================================
  Files         413      411       -2     
  Lines       27471    26070    -1401     
  Branches     5811     5315     -496     
==========================================
- Hits         9656     7759    -1897     
- Misses      14776    16001    +1225     
+ Partials     3039     2310     -729     

Flag	Coverage Δ
unittests-aries-vcx	29.76% <78.87%> (-5.39%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files Changed	Coverage Δ
aries_vcx/tests/test_creds_proofs.rs	81.81% <ø> (-0.41%)	⬇️
.../msg_fields/protocols/connection/invitation/mod.rs	60.00% <66.66%> (+10.00%)	⬆️
aries_vcx/src/protocols/connection/generic/mod.rs	9.60% <72.72%> (+9.59%)	⬆️
aries_vcx/tests/test_creds_proofs_revocations.rs	79.80% <75.58%> (+0.02%)	⬆️
aries_vcx/tests/utils/scenarios.rs	78.97% <78.79%> (+1.36%)	⬆️
aries_vcx/tests/utils/test_agent.rs	78.94% <78.94%> (ø)
aries_vcx/tests/test_connection.rs	80.00% <79.62%> (+5.44%)	⬆️
aries_vcx/tests/test_pool.rs	83.49% <81.52%> (-0.33%)	⬇️
aries_vcx/src/handlers/util.rs	16.66% <100.00%> (+3.72%)	⬆️
aries_vcx/tests/test_mysql_wallet.rs	92.30% <100.00%> (+1.39%)	⬆️

... and 106 files with indirect coverage changes