Issue #847: Prover Handler Types

[gmulhearn]

Implements #847

I went with the approach of keeping the legacy structures for now, they aren't toooo bad...

Changes revolve around changing the following handler APIs:

retrieve_credentials(&self, profile: &Arc<dyn Profile>) -> VcxResult<RetrievedCredentials>

generate_presentation(
        &mut self,
        profile: &Arc<dyn Profile>,
        credentials: SelectedCredentials,
        self_attested_attrs: HashMap<String, String>,
    ) -> VcxResult<()>

And then piping thru the typing in aries_vcx internally. And serde_json-ing the types externally (i.e. in our libvcx consumer code). The libvcx JSON strings should be backwards compatible still (which hopefully the CI is testing/enforcing).

[codecov-commenter]

Codecov Report

Merging #848 (60ecb3c) into main (9f2e922) will decrease coverage by 0.03%.
The diff coverage is 74.53%.

@@            Coverage Diff             @@
##             main     #848      +/-   ##
==========================================
- Coverage   48.88%   48.86%   -0.03%     
==========================================
  Files         428      429       +1     
  Lines       34134    34165      +31     
  Branches     7517     7533      +16     
==========================================
+ Hits        16687    16694       +7     
- Misses      12294    12313      +19     
- Partials     5153     5158       +5     

Flag	Coverage Δ
unittests-aries-vcx	48.82% <74.53%> (-0.04%)	⬇️

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

Impacted Files	Coverage Δ
...rc/protocols/proof_presentation/prover/messages.rs	19.56% <0.00%> (ø)
aries_vcx/src/handlers/proof_presentation/types.rs	46.80% <46.80%> (ø)
...ries_vcx/src/handlers/proof_presentation/prover.rs	55.00% <50.00%> (-0.72%)	⬇️
aries_vcx/src/common/proofs/prover/prover.rs	45.71% <66.66%> (ø)
...ion/prover/states/presentation_request_received.rs	58.69% <66.66%> (ø)
aries_vcx/tests/test_creds_proofs_revocations.rs	86.28% <66.66%> (-0.02%)	⬇️
aries_vcx/tests/test_creds_proofs.rs	86.89% <72.54%> (-0.41%)	⬇️
aries_vcx/tests/utils/devsetup_agent.rs	72.23% <83.33%> (ø)
...es_vcx/src/common/proofs/prover/prover_internal.rs	81.01% <90.76%> (+2.03%)	⬆️
aries_vcx/tests/utils/scenarios.rs	81.06% <93.10%> (+0.07%)	⬆️
... and 1 more

... and 5 files with indirect coverage changes

[gmulhearn]

@Patrik-Stas pending CI confirmation on some of my latest commits, but should be ready to review.

If CI fails it should just be minor things I'll fix tomorrow!

[bobozaur]

These comments, @gmulhearn ... They are just beautiful.

[Patrik-Stas]

very nice 👍