feat: add question answer protocol

[sabejensen]

Summary of Changes

Added a question answer module (https://github.com/hyperledger/aries-rfcs/blob/main/features/0113-question-answer/README.md) to send and receive question messages and to send and receive answer messages with a valid response.

Pull Request Checklist

• All commits contain a DCO Signed-off-by line (we use the DCO GitHub app to enforce this).
• Updated LICENSE-3RD-PARTY.md for any added dependencies or vendored components.
• Added tests for changed code (run scripts/preflight to run tests and check code style).
• Prefixed code comments with GitHub nick and an appropriate prefix.
• Coding style is consistent with the rest of the framework.
• Updated documentation for changed code and new or modified features.

[codecov-commenter]

Codecov Report

Merging #557 (6f1fae4) into main (a717a58) will decrease coverage by 0.27%.
The diff coverage is 74.33%.

@@            Coverage Diff             @@
##             main     #557      +/-   ##
==========================================
- Coverage   87.76%   87.49%   -0.28%     
==========================================
  Files         439      457      +18     
  Lines       10854    11080     +226     
  Branches     1837     1864      +27     
==========================================
+ Hits         9526     9694     +168     
- Misses       1267     1324      +57     
- Partials       61       62       +1     

Impacted Files	Coverage Δ
...rc/modules/question-answer/models/ValidResponse.ts	25.00% <25.00%> (ø)
...rc/modules/question-answer/QuestionAnswerModule.ts	52.77% <52.77%> (ø)
.../question-answer/services/QuestionAnswerService.ts	57.14% <57.14%> (ø)
...s/question-answer/handlers/AnswerMessageHandler.ts	71.42% <71.42%> (ø)
...question-answer/handlers/QuestionMessageHandler.ts	71.42% <71.42%> (ø)
...question-answer/repository/QuestionAnswerRecord.ts	89.28% <89.28%> (ø)
...odules/question-answer/messages/QuestionMessage.ts	95.65% <95.65%> (ø)
packages/core/src/agent/Agent.ts	95.89% <100.00%> (+0.05%)	⬆️
packages/core/src/index.ts	100.00% <100.00%> (ø)
...rc/modules/question-answer/QuestionAnswerEvents.ts	100.00% <100.00%> (ø)
... and 10 more

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[TimoGlastra]

Nice work @seajensen.

Only thing I'm thinking is whether we want to put this in core or ext? E.g push notifications lives in ext, QA is also not part of AIP so should it also live in ext? Would be good to have some consistency in what goed where, but I do see the potential of this getting added to the core package.

[genaris]

Nice work @seajensen.

Only thing I'm thinking is whether we want to put this in core or ext? E.g push notifications lives in ext, QA is also not part of AIP so should it also live in ext? Would be good to have some consistency in what goed where, but I do see the potential of this getting added to the core package.

First of all, good work @seajensen! It's great to see how easy it becomes to create modules implementing new protocols in AFJ.

This is a good point @TimoGlastra. I think the choice could depend on the current RFC lifecycle status, which is eventually related to AIPs (i.e. most ACCEPTED RFCs become part of an AIP version). Push Notification Native RFC is currently PROPOSED, so it is not likely to be widely used right now and it's fine in ext repository. In this particular case, Question/Answer is DEMONSTRATED, which is not so different.

If we choose to put it in aries-javascript-framework-ext repository, I think there are a few classes/methods to be exposed (for instance BaseRecord and createOutboundMessage). This will be useful also for anyone who wants to use custom protocols in AFJ. I can create a PR including these exports shortly.

[TimoGlastra]

We had a discussion about this during the WG call, but I forgot the outcome. Do we add this to the core of the framework, or make it an extension?

@JamesKEbert @seajensen do you know what the outcome was?

[JamesKEbert]

I unfortunately I was out sick during that WG call, but I recall @seajensen communicating to me that we were going to merge it in.

[TimoGlastra]

@seajensen if you can resolve the conflicts we can get this merged!