feat(fields): Add deprecated field mappings module

Doug Barrettrequested to merge
dbarrett/deprecated_fields into master

Add Labkit::Fields::Deprecated module that maps deprecated logging field names to their standardized replacements. This supports the Observability Field Standardisation initiative.

The module provides:

  • all - returns list of all deprecated field names
  • standard_field_for(deprecated) - returns the standard field name
  • deprecated?(field) - checks if a field is deprecated

Also adds constant_name_for helper to Labkit::Fields for reverse lookup of field constants by value.

See: Observability Field Standardization gitlab-org/quality/quality-engineering/team-tasks#4094 (closed)

Merge request reports