SNOW-1009042: Replace Portable.BouncyCastle with BouncyCastle.Cryptography

[sfc-gh-pbulawa]

Description

Replace unmaintained Portable.BouncyCastle with BouncyCastle.Cryptography.

Checklist

• Code compiles correctly
• Code is formatted according to Coding Conventions
• Created tests which fail without the change (if possible)
• All tests passing (dotnet test)
• Extended the README / documentation, if necessary
• Provide JIRA issue id (if possible) or GitHub issue id in PR name

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (fa09941) 83.75% compared to head (1feab77) 83.66%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #857      +/-   ##
==========================================
- Coverage   83.75%   83.66%   -0.09%     
==========================================
  Files          89       89              
  Lines        9344     9344              
  Branches      861      861              
==========================================
- Hits         7826     7818       -8     
- Misses       1295     1302       +7     
- Partials      223      224       +1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.