Hash Rfq privateData

[diehuxx]

Implement min bar changes laid out in this spec change: TBD54566975/tbdex#294
In further PRs, we could improve ergonomics around validating/disclosing specific privateData fields.

See also equivalent PR in tbdex-js: TBD54566975/tbdex-js#215

[codecov-commenter]

Codecov Report

Merging #222 (da99f4c) into main (bd505a5) will increase coverage by 4.95%.
Report is 5 commits behind head on main.
The diff coverage is 70.68%.

❗ Current head da99f4c differs from pull request most recent head 5d46ac0. Consider uploading reports for the commit 5d46ac0 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #222      +/-   ##
==========================================
+ Coverage   79.39%   84.34%   +4.95%     
==========================================
  Files          35       38       +3     
  Lines         820     1124     +304     
  Branches       75      114      +39     
==========================================
+ Hits          651      948     +297     
+ Misses        133      124       -9     
- Partials       36       52      +16     

Components	Coverage Δ
protocol	85.85% <81.81%> (-2.16%)	⬇️
httpclient	78.34% <70.45%> (-2.48%)	⬇️

[diehuxx]

Offline, @mistermoe @jiyoontbd @KendallWeihe @kirahsapong and I discussed a DX improvement:

Rename classes with the Unhashed* prefix to instead of Create* prefix, e.g. UnhashedRfqData -> CreateRfqData and UnhashedPayinMethod -> CreatePayinMethod.

We came to this decision because we believe that introducing the concept of hashing when sdk consumer is trying to Rfq.create() causes confusion, and hashing should be an implementation detail. If they choose, the developer can learn more about hashing through either the ktdocs of the relevant types like RfqData or RfqPrivateData, or the tbdex protocol spec, which outlines the structure of the Rfq returned from calling create()

I'll push a commit for this in juuuust a sec.

[jiyoonie9]

couple nits for doc, not blocking. well done 🎉