Provisioning: Begin using secrets store (#108044)

- Provisioning: Begin using secrets store
- Refactor integration with secrets store
- Add back the legacy service
- Separate concerns for encrypt and decrypt
- Handle update within Encrypt function
- Add interface for secure value service
- Add feature flag for using secrets service
- Add the dual service for temporary solution.

* Add first integration tests for encrypted tokens
* Add integration test for app platform secrets
* Validate it has the name or not
* Create wire provider
* Always save to the secret if provided secret

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Co-authored-by: Roberto Jimenez Sanchez <roberto.jimenez@grafana.com>
Co-authored-by: Roberto Jiménez Sánchez <jszroberto@gmail.com>

pkg/services/featuremgmt/models.go

@@ -6,6 +6,7 @@ import (
 	"encoding/json"
 )
 
+//go:generate mockery --name FeatureToggles --structname MockFeatureToggles --inpackage --filename feature_toggles_mock.go --with-expecter
 type FeatureToggles interface {
 	// IsEnabled checks if a feature is enabled for a given context.
 	// The settings may be per user, tenant, or globally set in the cloud