Enable groupbyatttrs processor - take two

[pmm-sumo]

The previous PR unfortunately got in between switch master -> main and got merged into master (it seems it's the only one affected). Since it got accepted, can we re-merge it?

Description:

Introduces processor for grouping the trace or log records by specified key values, and then extracting the attributes from the record to resource level.

This initiative is broken down into 3 separate PRs:

1. Config (already merged)

2. The processor logic (already merged)

👉 3. Enabling the component (this PR)

Example: consider having such input:

InstrumentationLibraryLogs #0
LogRecord #0
Timestamp: 1606158664897894000
Severity:
ShortName:
Body: STRING("foo")
Attributes:
     -> action: STRING(login)
     -> namespace_name: STRING(kube-apiserver-docker-desktop)
     -> pod_name: STRING(kube-system)

With following config:

groupbyattrs:
  group_by_keys:
    - pod_name
    - namespace_name

The output is going to be:

Resource labels:
     -> namespace_name: STRING(kube-apiserver-docker-desktop)
     -> pod_name: STRING(kube-system)
InstrumentationLibraryLogs #0
LogRecord #0
Timestamp: 1606158617133076000
Severity:
ShortName:
Body: STRING("foo")
Attributes:
     -> action: STRING(login)

Link to tracking Issue: #1884

Testing: Unit tests added, manual tests performed on logs and traces

Documentation: Processor README.md included

[codecov]

Codecov Report

Merging #2635 (8ba128b) into main (5efd35d) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main    #2635   +/-   ##
=======================================
  Coverage   91.37%   91.37%           
=======================================
  Files         433      433           
  Lines       21530    21531    +1     
=======================================
+ Hits        19674    19675    +1     
  Misses       1390     1390           
  Partials      466      466           

Flag	Coverage Δ
integration	69.13% <0.00%> (+0.20%)	⬆️
unit	90.28% <100.00%> (+<0.01%)	⬆️

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

Impacted Files	Coverage Δ
cmd/otelcontribcol/components.go	87.50% <100.00%> (+0.15%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 5efd35d...8ba128b. Read the comment docs.

[tigrannajaryan]

Copy of #2263 so already reviewed. Merging.