Error source HTTP client middleware

[marefr]

Alternative to #1102

Moves backend.ErrorSource related implementation to a new package status. This tries to keep backward compatibility by keeping type aliases in the backend package referencing the new status package.

The main motivation behind this change is that having the backend.ErrorSource makes it basically impossible for any other package to make use of this if that package is imported by the backend package since it creates a circular dependency.

Seems like gorelease doesn't agree these type alias changes are compatible. In my head they should be 🤔

# github.com/grafana/grafana-plugin-sdk-go/backend
## incompatible changes
DataResponse.ErrorSource: changed from ErrorSource to github.com/grafana/grafana-plugin-sdk-go/experimental/status.Source
DefaultErrorSource: changed from ErrorSource to github.com/grafana/grafana-plugin-sdk-go/experimental/status.Source
ErrDataResponseWithSource: changed from func(Status, ErrorSource, string) DataResponse to func(Status, github.com/grafana/grafana-plugin-sdk-go/experimental/status.Source, string) DataResponse
ErrorSource: changed from ErrorSource to github.com/grafana/grafana-plugin-sdk-go/experimental/status.Source
ErrorSourceDownstream: changed from ErrorSource to github.com/grafana/grafana-plugin-sdk-go/experimental/status.Source
ErrorSourceFromHTTPStatus: changed from func(int) ErrorSource to func(int) github.com/grafana/grafana-plugin-sdk-go/experimental/status.Source
ErrorSourcePlugin: changed from ErrorSource to github.com/grafana/grafana-plugin-sdk-go/experimental/status.Source
FrameResponseWithErrorAndSource: changed from func(github.com/grafana/grafana-plugin-sdk-go/data.Framer, error, ErrorSource) *DataResponse to func(github.com/grafana/grafana-plugin-sdk-go/data.Framer, error, github.com/grafana/grafana-plugin-sdk-go/experimental/status.Source) *DataResponse
WithErrorSource: changed from func(context.Context, ErrorSource) error to func(context.Context, github.com/grafana/grafana-plugin-sdk-go/experimental/status.Source) error
## compatible changes
ErrorSourceFromHTTPError: added
IsDownstreamHTTPError: added

# github.com/grafana/grafana-plugin-sdk-go/backend/httpclient
## compatible changes
ErrorSourceMiddleware: added
ErrorSourceMiddlewareName: added

# github.com/grafana/grafana-plugin-sdk-go/experimental/errorsource
## incompatible changes
Error.ErrorSource: changed from func() github.com/grafana/grafana-plugin-sdk-go/backend.ErrorSource to func() github.com/grafana/grafana-plugin-sdk-go/experimental/status.Source
Error.Source: changed from func() github.com/grafana/grafana-plugin-sdk-go/backend.ErrorSource to func() github.com/grafana/grafana-plugin-sdk-go/experimental/status.Source
FromStatus: changed from func(github.com/grafana/grafana-plugin-sdk-go/backend.Status) github.com/grafana/grafana-plugin-sdk-go/backend.ErrorSource to func(github.com/grafana/grafana-plugin-sdk-go/backend.Status) github.com/grafana/grafana-plugin-sdk-go/experimental/status.Source
New: changed from func(error, github.com/grafana/grafana-plugin-sdk-go/backend.ErrorSource, github.com/grafana/grafana-plugin-sdk-go/backend.Status) Error to func(error, github.com/grafana/grafana-plugin-sdk-go/experimental/status.Source, github.com/grafana/grafana-plugin-sdk-go/backend.Status) Error
SourceError: changed from func(github.com/grafana/grafana-plugin-sdk-go/backend.ErrorSource, error, bool) Error to func(github.com/grafana/grafana-plugin-sdk-go/experimental/status.Source, error, bool) Error

# github.com/grafana/grafana-plugin-sdk-go/experimental/slo
## incompatible changes
FromStatus: changed from func(github.com/grafana/grafana-plugin-sdk-go/backend.Status) github.com/grafana/grafana-plugin-sdk-go/backend.ErrorSource to func(github.com/grafana/grafana-plugin-sdk-go/backend.Status) github.com/grafana/grafana-plugin-sdk-go/experimental/status.Source

# github.com/grafana/grafana-plugin-sdk-go/experimental/status
## compatible changes
package added

# summary
Inferred base version: v0.2[5](https://github.com/grafana/grafana-plugin-sdk-go/actions/runs/11290062261/job/31401119632?pr=1106#step:5:6)2.0
Suggested version: v0.253.0

[ivanahuckova]

Awesome cleanup! Left some comments.

[ivanahuckova]

LGTM! Things that we need to improve in follow up:

• We should probably export errorWithSourceImpl and use it in experimental/errorsource instead of Error to ensure that all methods are working as intended with a new middleware. Specifically we need Response to work.
• We should add methods/options that add error source, but will not override it if it exists
• Deprecate experimental/errorsource and point plugin developers use non-experimental versions of functions.
• In pkg/infra/httpclient/httpclientprovider/http_client_provider.go we need to add ErrorSource middleaware so built in plugin case use it.

[ivanahuckova]

Left couple more comments and questions

[wbrowne]

LGTM