[pdata/pcommon] Remove HTML-escaping of special chars when converting Map and Slice Values to JSON strings

[zpzhuSplunk]

Description
Value.AsString() produces inconsistent output for string values containing HTML-special characters (<, >, &). When the Value is of type ValueTypeStr, the raw string is returned with no escaping. However, when the Value is of type ValueTypeMap or ValueTypeSlice, the standard library's json.Marshal HTML-escapes those characters to their Unicode escape sequences (\u003c, \u003e, \u0026).
This fix replaces encoding/json's json.Marshal with github.com/goccy/go-json's json.MarshalWithOption using the json.DisableHTMLEscape() option, so that Map and Slice values are serialized to JSON without HTML escaping, consistent with the behavior of plain string values.
Link to tracking issue
Fixes #14662

Testing
Added two new test cases to TestValueAsString:
map_with_html_chars: verifies that a Map containing the string html&value is serialized as {"key":"html&value"} (not {"key":"\u003cb\u003ehtml\u0026value\u003c/b\u003e"}).
slice_with_html_chars: verifies that a Slice containing strings link and a]>b&c is serialized as ["link","a]>b&c"].
All existing tests in pdata/pcommon continue to pass.

Documentation
A changelog entry was added at .chloggen/fix-value-asstring-html-escaping.yaml describing the bug fix for the pkg/pdata component.

[zpzhuSplunk]

We added a new dependency goccy/go-json for pdata/pcommon. All modules depending on this will need a go.mod update.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.82%. Comparing base (f21ec9e) to head (611907a).
⚠️ Report is 195 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #14670   +/-   ##
=======================================
  Coverage   91.81%   91.82%           
=======================================
  Files         680      680           
  Lines       43043    43043           
=======================================
+ Hits        39522    39525    +3     
+ Misses       2449     2447    -2     
+ Partials     1072     1071    -1     

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

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[mx-psi]

Thanks for your PR, can we confirm first with the specification what the recommended approach is for this? There was a recent change (see open-telemetry/opentelemetry-specification/pull/4848) that established some guidance on representing complex attributes, I would like to understand what the preferred approach is so that the Collector is as consistent as feasible with SDKs

[github-actions]

This PR was marked stale due to lack of activity. It will be closed in 14 days.

[github-actions]

This PR was marked stale due to lack of activity. It will be closed in 14 days.

[github-actions]

This PR was marked stale due to lack of activity. It will be closed in 14 days.