Populate fields from new payload

[fractalwrench]

Goal

Populates the SessionMessage with fields from the new payload. This is not hooked up yet so won't send any changes to our production API.

Testing

Added unit test coverage.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 80.24%. Comparing base (8210d0d) to head (f88ca2d).

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #557      +/-   ##
==========================================
+ Coverage   80.20%   80.24%   +0.04%     
==========================================
  Files         413      413              
  Lines       11000    11014      +14     
  Branches     1618     1618              
==========================================
+ Hits         8822     8838      +16     
  Misses       1532     1532              
+ Partials      646      644       -2     

Files	Coverage Δ
...bracesdk/capture/envelope/SessionEnvelopeSource.kt	100.00% <100.00%> (ø)
...brace/android/embracesdk/payload/SessionMessage.kt	100.00% <100.00%> (ø)
.../embracesdk/session/message/FinalEnvelopeParams.kt	88.37% <100.00%> (+0.56%)	⬆️
...d/embracesdk/session/message/PayloadFactoryImpl.kt	92.77% <100.00%> (+0.27%)	⬆️
...acesdk/session/message/V2PayloadMessageCollator.kt	100.00% <100.00%> (ø)

... and 1 file with indirect coverage changes

[bidetofevil]

LGTM