RUMM-2699: Remove RumEventSourceProvider

[0xnm]

What does this PR do?

This change removes RumEventSourceProvider, because we shouldn't access CoreFeature (it won't be exposed as public API), so we cannot read CoreFeature#sourceName at the DatadogRumMonitor construction time and should read DatadogContext#source instead which is available in the Event Write Context.

Calls to RumEventSourceProvider are replaced by the companion extensions of the corresponding Source objects which try to parse the value from DatadogContext#source in the safe manner.

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• Make sure you discussed the feature or bugfix with the maintaining team in an Issue
• Make sure each commit and the PR mention the Issue number (cf the CONTRIBUTING doc)

[codecov-commenter]

Codecov Report

Merging #1119 (0bab8ec) into feature/sdkv2 (d71fe7b) will decrease coverage by 0.06%.
The diff coverage is 93.62%.

@@                Coverage Diff                @@
##           feature/sdkv2    #1119      +/-   ##
=================================================
- Coverage          82.49%   82.43%   -0.06%     
=================================================
  Files                348      348              
  Lines              11409    11380      -29     
  Branches            1910     1911       +1     
=================================================
- Hits                9411     9380      -31     
+ Misses              1421     1419       -2     
- Partials             577      581       +4     

Impacted Files	Coverage Δ
...n/com/datadog/android/core/internal/CoreFeature.kt	91.06% <ø> (-0.04%)	⬇️
.../main/kotlin/com/datadog/android/rum/RumMonitor.kt	77.08% <ø> (-0.92%)	⬇️
...d/rum/internal/domain/scope/RumApplicationScope.kt	100.00% <ø> (ø)
...droid/rum/internal/domain/scope/RumSessionScope.kt	91.43% <ø> (-0.12%)	⬇️
...d/rum/internal/domain/scope/RumViewManagerScope.kt	98.15% <ø> (-0.07%)	⬇️
.../android/rum/internal/monitor/DatadogRumMonitor.kt	92.61% <ø> (+0.52%)	⬆️
...ndroid/telemetry/internal/TelemetryEventHandler.kt	89.23% <0.00%> (-1.68%)	⬇️
...android/rum/internal/ndk/DatadogNdkCrashHandler.kt	85.28% <66.67%> (-4.01%)	⬇️
...ndroid/rum/internal/domain/scope/RumActionScope.kt	98.56% <100.00%> (-0.02%)	⬇️
...g/android/rum/internal/domain/scope/RumEventExt.kt	94.42% <100.00%> (+0.67%)	⬆️
... and 13 more