Removes request/response connection/hop headers for call resource in similar
manner as Go's reverse proxy functions. Also removes Prometheus datasource
custom call resource header manipulation in regards to hop-by-hop headers.
Fixes#60076
Ref #58646
Co-authored-by: Will Browne <wbrowne@users.noreply.github.com>
* plugin client returns error base
* fix api test
* add plugin client test
* add fallback err
* fix linting
* wip
* replace bad query
* template is an error
* failing test of templated error
* add one test passing
* fix failing test
* move test
* rename ErrBadQuery to ErrQueryValidationFailure
* tidy diff
* Change to one error per specific error kind
* last err + fix test
* fix imports
* more tests
* keep req vars together
Co-authored-by: Marcus Efraimsson <marcus.efraimsson@gmail.com>
