Encryption: De-duplicate encryption code with extensible service (#52472)

* Encryption: De-duplicate encryption code with extensible service

* Fix Wire injections

* Fix tests

* Register reload handler

pkg/services/encryption/provider/cipher_aescfb_test.go

@@ -0,0 +1,20 @@
+package provider
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/stretchr/testify/require"
+)
+
+func Test_aesCfbCipher(t *testing.T) {
+	cipher := aesCfbCipher{}
+	ctx := context.Background()
+
+	encrypted, err := cipher.Encrypt(ctx, []byte("grafana"), "1234")
+	require.NoError(t, err)
+	assert.NotNil(t, encrypted)
+	assert.NotEmpty(t, encrypted)
+}