Add internal error payload models

[fractalwrench]

Goal

Adds model classes for the new internal error payload. This is mostly generated via OpenAPI but tweaked manually for style reasons.

Testing

Added unit test to confirm new model can be constructed from old one.

[codecov]

Codecov Report

Attention: Patch coverage is 89.74359% with 4 lines in your changes are missing coverage. Please review.

Project coverage is 79.44%. Comparing base (d08aac0) to head (11be2c2).

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #512      +/-   ##
==========================================
+ Coverage   79.37%   79.44%   +0.07%     
==========================================
  Files         392      395       +3     
  Lines       10771    10795      +24     
  Branches     1597     1599       +2     
==========================================
+ Hits         8549     8576      +27     
+ Misses       1579     1575       -4     
- Partials      643      644       +1     

Files	Coverage Δ
.../embracesdk/internal/payload/ExceptionErrorInfo.kt	100.00% <100.00%> (ø)
...droid/embracesdk/internal/payload/ExceptionInfo.kt	100.00% <100.00%> (ø)
...droid/embracesdk/internal/payload/InternalError.kt	100.00% <100.00%> (ø)
...roid/embracesdk/internal/payload/SessionPayload.kt	100.00% <100.00%> (ø)
.../embracesdk/logging/EmbraceInternalErrorService.kt	90.19% <100.00%> (ø)
...ava/io/embrace/android/embracesdk/payload/Crash.kt	100.00% <100.00%> (ø)
...android/embracesdk/payload/LegacyExceptionError.kt	95.23% <100.00%> (ø)
...a/io/embrace/android/embracesdk/payload/Session.kt	100.00% <100.00%> (ø)
...roid/embracesdk/payload/extensions/CrashFactory.kt	78.57% <100.00%> (ø)
.../android/embracesdk/payload/LegacyExceptionInfo.kt	47.61% <75.00%> (ø)
... and 1 more

... and 3 files with indirect coverage changes

[priettt]

nit: is the full import needed? if it's because there's two ExceptionInfo classes, should we rename one of them?

[fractalwrench]

Yeah it's needed to disambiguate right now. @priettt how about adding a prefix, like LegacyExceptionInfo, to affected classes? I'll roll that out across the other PRs tomorrow if you're happy with the approach