feat: add emitting of transaction data inside context trace data

[JoshuaMoelans]

fixes https://github.com/getsentry/sentry-native/issues/1074 related to https://github.com/getsentry/team-sdks/issues/95

ToDo:

• [x] emit transaction data through context trace data

• [x] emit transaction data through context trace data in any event being sent during a transaction

• [x] add/update proper test for this

• [x] add to changelog

  	Messages
  :book:	Do not forget to update Sentry-docs with your feature once the pull request gets approved.

  Generated by :no_entry_sign: dangerJS against 3997178aa1e719c2f56202885b8bec30f6688764

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 50.00000% with 7 lines in your changes missing coverage. Please review.

Project coverage is 82.55%. Comparing base (34a9901) to head (3997178). Report is 1 commits behind head on master.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #1075 +/- ## ========================================== - Coverage 82.67% 82.55% -0.12% ========================================== Files 53 53 Lines 7717 7729 +12 Branches 1213 1214 +1 ========================================== + Hits 6380 6381 +1 - Misses 1225 1235 +10 - Partials 112 113 +1 ```