RUM-9491: Moving all changes into v3

[satween]

What does this PR do?

In this PR I just want to merge everything made for SDK v3 into feature/v3 branch and use it as a base for further development. All chages here was already reviewed in corresponding pull requests

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 1 line in your changes missing coverage. Please review.

Project coverage is 67.70%. Comparing base (f8f769c) to head (f67cd31).

Files with missing lines	Patch %	Lines
...dog/legacy/trace/common/sampling/SamplingRule.java	0.00%	1 Missing :warning:

Additional details and impacted files

@@              Coverage Diff               @@
##           feature/v3    #2660      +/-   ##
==============================================
- Coverage       70.01%   67.70%   -2.31%     
==============================================
  Files             821      821              
  Lines           30644    30605      -39     
  Branches         5158     5158              
==============================================
- Hits            21454    20721     -733     
- Misses           7754     8521     +767     
+ Partials         1436     1363      -73     

Files with missing lines	Coverage Δ
...main/java/com/datadog/exec/CommonTaskExecutor.java	47.83% <ø> (ø)
...ain/java/com/datadog/exec/DaemonThreadFactory.java	100.00% <ø> (ø)
...main/java/com/datadog/legacy/trace/api/Config.java	0.00% <ø> (ø)
...java/com/datadog/legacy/trace/api/DDSpanTypes.java	0.00% <ø> (ø)
...main/java/com/datadog/legacy/trace/api/DDTags.java	0.00% <ø> (ø)
...a/com/datadog/legacy/trace/api/DDTraceApiInfo.java	0.00% <ø> (ø)
.../legacy/trace/common/sampling/AbstractSampler.java	0.00% <ø> (ø)
...tadog/legacy/trace/common/sampling/AllSampler.java	0.00% <ø> (ø)
...cy/trace/common/sampling/DeterministicSampler.java	0.00% <ø> (ø)
...cy/trace/common/sampling/RateByServiceSampler.java	0.00% <ø> (ø)
... and 212 more

... and 37 files with indirect coverage changes

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