Fix/notification problem report

[bobozaur]

As per the RFC the ProblemReport message can be a part of the notification message family (which only contains the ack message that's borrowed to other protocols).

This PR adds a ProblemReport message to the protocol to match the AFJ implementation (which is, technically, correct).

[codecov-commenter]

Codecov Report

Merging #833 (e9b5339) into main (a7cc540) will increase coverage by 0.34%.
The diff coverage is 33.33%.

❗ Current head e9b5339 differs from pull request most recent head 3de6bc3. Consider uploading reports for the commit 3de6bc3 to get more accurate results

@@            Coverage Diff             @@
##             main     #833      +/-   ##
==========================================
+ Coverage   48.73%   49.07%   +0.34%     
==========================================
  Files         404      412       +8     
  Lines       32680    33575     +895     
  Branches     7192     7449     +257     
==========================================
+ Hits        15925    16477     +552     
- Misses      11910    11985      +75     
- Partials     4845     5113     +268     

Flag	Coverage Δ
unittests-aries-vcx	49.04% <33.33%> (+0.33%)	⬆️

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

Impacted Files	Coverage Δ
...ies_vcx/src/common/primitives/credential_schema.rs	46.45% <ø> (ø)
aries_vcx/src/handlers/util.rs	16.25% <0.00%> (-0.21%)	⬇️
aries_vcx/src/protocols/connection/generic/mod.rs	35.58% <ø> (ø)
aries_vcx/src/protocols/connection/invitee/mod.rs	69.44% <ø> (ø)
aries_vcx/src/protocols/issuance/actions.rs	35.29% <0.00%> (-5.62%)	⬇️
...vcx/src/protocols/issuance/holder/state_machine.rs	42.41% <0.00%> (-0.31%)	⬇️
...vcx/src/protocols/issuance/issuer/state_machine.rs	48.65% <0.00%> (ø)
...ocols/mediated_connection/invitee/state_machine.rs	51.98% <ø> (ø)
...rc/protocols/proof_presentation/prover/messages.rs	23.07% <0.00%> (-5.05%)	⬇️
...otocols/proof_presentation/prover/state_machine.rs	31.42% <0.00%> (-0.74%)	⬇️
... and 16 more

... and 28 files with indirect coverage changes