RUM-8582: Add kotlin compiler plugin environment

[ambushwork]

What does this PR do?

This PR :

• sets up the necessary environment and dependency for developing Kotlin Complier Plugin.
• Adds the basic Kotlin Complier Plugin extension registering flow.
• Adds a dummy ComoposeTagTransformer for future development.

Motivation

RUM-8582

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

Attention: Patch coverage is 0% with 14 lines in your changes missing coverage. Please review.

Project coverage is 77.09%. Comparing base (d5346cd) to head (37c7e86).
Report is 4 commits behind head on feature/kotlin-compiler-plugin.

Files with missing lines	Patch %	Lines
...atadog/gradle/plugin/kcp/DatadogPluginRegistrar.kt	0.00%	6 Missing ⚠️
...datadog/gradle/plugin/kcp/ComposeTagTransformer.kt	0.00%	4 Missing ⚠️
...om/datadog/gradle/plugin/kcp/DatadogIrExtension.kt	0.00%	4 Missing ⚠️

Additional details and impacted files

@@                         Coverage Diff                          @@
##             feature/kotlin-compiler-plugin     #314      +/-   ##
====================================================================
- Coverage                             78.11%   77.09%   -1.02%     
- Complexity                              260      261       +1     
====================================================================
  Files                                    31       34       +3     
  Lines                                   941      956      +15     
  Branches                                113      113              
====================================================================
+ Hits                                    735      737       +2     
- Misses                                  151      165      +14     
+ Partials                                 55       54       -1     

Files with missing lines	Coverage Δ
...datadog/gradle/plugin/kcp/ComposeTagTransformer.kt	0.00% <0.00%> (ø)
...om/datadog/gradle/plugin/kcp/DatadogIrExtension.kt	0.00% <0.00%> (ø)
...atadog/gradle/plugin/kcp/DatadogPluginRegistrar.kt	0.00% <0.00%> (ø)

... and 1 file with indirect coverage changes

[0xnm]

why we are using outdated KAPT here? Is it for AutoService? Does it support KSP?

[ambushwork]

yes, it's for AutoService annotation processing, and AutoService doesn't work with KSP.