Extract session api to delegate

[fractalwrench]

Goal

Splits the EmbraceImpl implementation so the session API is implemented as a delegate. Future changesets will factor other related APIs into appropriate delegates.

Testing

Relied on existing test coverage.

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 78.41727% with 30 lines in your changes are missing coverage. Please review.

Project coverage is 80.71%. Comparing base (6a0dfaf) to head (2bb5ea3). Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #850      +/-   ##
==========================================
- Coverage   80.78%   80.71%   -0.08%     
==========================================
  Files         426      429       +3     
  Lines       11464    11483      +19     
  Branches     1748     1752       +4     
==========================================
+ Hits         9261     9268       +7     
- Misses       1448     1457       +9     
- Partials      755      758       +3     

Files	Coverage Δ
...in/java/io/embrace/android/embracesdk/Embrace.java	82.31% <100.00%> (-0.82%)	:arrow_down:
.../java/io/embrace/android/embracesdk/EmbraceImpl.kt	60.99% <100.00%> (-0.25%)	:arrow_down:
...android/embracesdk/EmbraceInternalInterfaceImpl.kt	91.66% <100.00%> (-2.39%)	:arrow_down:
.../embrace/android/embracesdk/utils/PropertyUtils.kt	85.71% <75.00%> (-6.60%)	:arrow_down:
...internal/api/delegate/NetworkRequestApiDelegate.kt	60.00% <60.00%> (ø)
...acesdk/internal/api/delegate/SessionApiDelegate.kt	31.25% <31.25%> (ø)
...mbracesdk/internal/api/delegate/LogsApiDelegate.kt	83.11% <83.11%> (ø)

... and 5 files with indirect coverage changes