[BUG] Controller outputs key vault keys as binary data, not a usable string

[jpachcuda]

Note: Make sure to check out known issues (https://akv2k8s.io/troubleshooting/known-issues/) before submitting

Components and versions
Select which component(s) the bug relates to with [X].

[X] Controller, version: 1.5.0 (docker image tag)
[ ] Env-Injector (webhook), version: x.x.x (docker image tag)
[ ] Other

Describe the bug
Since v1.5.0, secrets of type key are not being pulled in the proper format.

To Reproduce
Install akv2k8s helm chart v2.5.1
Create a key in a key vault that can be accessed from the cluster akv2k8s is installed on.
Create an AzureKeyVaultSecret for the key

apiVersion: spv.no/v1
kind: AzureKeyVaultSecret
metadata:
  name: test-key
  namespace: akv2k8s-test
spec:
  vault:
    name: test-keys-kv
    object:
      name: test-key
      type: key
  output:
    secret:
      name: test-key
      dataKey: apiKey

Decoding the secret will show:

apiKey: "��#\x14;9�}����\x11�u�+^�x�lG[��X����Ӎ�3���!E݆��L�h����y\v\a\x1F�\x12�*\x11�\\5�:Ѯo�v\f�����\x1D����\x1E��+&\a.��e\x04�:Z� �cW�\x14J\x1D޺�\ed\x04\x11����e|t��9p�f\x15rѹ��y\x0F1�D�{�]W5h����˒^���(��g��CV\v�'E\x0E�1\x19�\0O\at��\x11cP]�\x03�>������x�\x115���gL�NF!�L�����.� ���k��c\x17�^\x17�yGO\x13�\bVq�ҫ�&�\x14��V�\f\x05����S\x0F����l\r"

Expected behavior
In previous versions of akv2k8s, the secret value would be formatted as a string:

apiKey: mc8jFDs5v33v67bkEYV1pyte93itbGBHW-K5WK2qk_jTjcczwv3jIUXdhoOYTNxomrDB1HkLBx-nEogqEZBcNcM60a5v5XYMxvGantsd8pud2h6G2ysmBy6GkWUEijpakCDcY1eSFEod3rqQG2QEEcfJ7KVlfHTfwzlwjmYVctG5_oB5DzHJRN97wl1XNWjQ2ujdy5Je19_vKJz0Z-2YQ1YLiydFDr0xGfcATwd0vKoRY1BdtgOqP
qyqu42A-3i9ETSTqINnTKNORiGITJivxvrBLuHFa8GLYxfdXhfAeUdPE2DaCFZxrdKroybDFMXBVoDNCZ359YRTD_Xg9-BsDQ

Additional context
I think I've identified how this problem was introduced, although I do not know the exact fix.

In older versions of akv2k8s, the getKey method returned a JSONWebKey struct that included url encoded base64 strings
https://pkg.go.dev/github.com/Azure/[email protected]+incompatible/services/keyvault/2016-10-01/keyvault#JSONWebKey

However, the azkeys package being used now returns a JSONWebKey struct that includes values that are of the type []byte. These are not being handled appropriately by the getKeys function as it seems they cannot be typecast to string.
https://pkg.go.dev/github.com/Azure/azure-sdk-for-go/sdk/security/keyvault/azkeys#JSONWebKey

azure-key-vault-to-kubernetes/pkg/azure/keyvault/client/service.go

Lines 104 to 112 in 647b715

	response, err := client.GetKey(ctx, vaultSpec.Object.Name, vaultSpec.Object.Version, &azkeys.GetKeyOptions{})
	if err != nil {
	return "", err
	}
	data := &response.Key.N
	return string(*data), nil
	}

It seems like the []byte data may be able to be converted properly by using one of the UnmarshalJSON functions included in azkeys, although I do not know exactly how this should be implemented. https://github.com/Azure/azure-sdk-for-go/blob/e9e6b6281766a4e71ea0ee0b7268692009e2794b/sdk/security/keyvault/azkeys/models_serde.go#L332