(feat): Add attribute_sort filter to weaver_forge

[jsuereth]

Add a filter that lets us perform attribute sorting the way we need to for semconv templates.

Also document other filters/tests added previously.

[codecov]

Codecov Report

Attention: Patch coverage is 90.90909% with 3 lines in your changes are missing coverage. Please review.

Project coverage is 75.5%. Comparing base (261e4f4) to head (879fed2).

❗ Current head 879fed2 differs from pull request most recent head 8f983ea. Consider uploading reports for the commit 8f983ea to get more accurate results

Files	Patch %	Lines
crates/weaver_forge/src/extensions/otel.rs	90.6%	3 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##            main    #144     +/-   ##
=======================================
+ Coverage   75.3%   75.5%   +0.2%     
=======================================
  Files         42      42             
  Lines       2367    2400     +33     
=======================================
+ Hits        1783    1813     +30     
- Misses       584     587      +3     

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[lquerel]

I made a suggestion you could integrate before to merge this PR.
As, it's not blocking, I approved the PR.