Change the way resource attributes are populated (unbreaks a 2.0 change)

[mariomac]

After discussing internally with some users, there was a misinterpretation about the resource labels and attributes, so this PR:

• Restores the meta_source_labels from version 1.9, but deprecates it and shows a warning if a user is still using it. There are new users adopting this option in the past days and would not be nice that one week after configuring everything, Beyla 2.0 breaks it.

• Adds the resource_labels option as a map, allowing to specify any OTEL resource attribute (not only limited to service name and NS). Currently only name and namespace are considered, but in a following PR, any other attribute is going to be forwarded as a resource attribute.

• The resource.opentelemetry.io/ annotations are not configurable anymore, as they are an opinionated and standard way to configure any resource attribute, not only service name and namespace (like OTEL_RESOURCE_ATTRIBUTES). In a following PR, we will handle any resource attribute specified in this format.

[codecov]

Codecov Report

Attention: Patch coverage is 46.66667% with 16 lines in your changes missing coverage. Please review.

Project coverage is 71.14%. Comparing base (285162b) to head (b548ef0).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
pkg/components/beyla.go	20.00%	12 Missing and 4 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1565      +/-   ##
==========================================
- Coverage   71.15%   71.14%   -0.01%     
==========================================
  Files         197      197              
  Lines       19671    19689      +18     
==========================================
+ Hits        13996    14007      +11     
- Misses       4995     5000       +5     
- Partials      680      682       +2     

Flag	Coverage Δ
integration-test	53.24% <13.33%> (-0.08%)	⬇️
k8s-integration-test	53.79% <46.66%> (+0.43%)	⬆️
oats-test	34.40% <13.33%> (+0.14%)	⬆️
unittests	47.30% <43.33%> (-0.03%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[grcevski]

LGTM! Just a question because I might've missed it, do we have an integration test with the new way to override the name?

[mariomac]

@grcevski we have it from the previous implementation. We just took care that current tests were not broken after changing the spec.