Is your feature request related to a problem? Please describe.
The secretserver provider is unable to login to our secret server because I can't specify a Domain in the SecretStore. Our secret server is connected to AD and a domain must be specified in the /oauth2/token request.

Describe the solution you'd like
A domain field in the provider config:

apiVersion: external-secrets.io/v1
kind: SecretStore
metadata:
  name: secret-server-store
spec:
  provider:
    secretserver:
      domain: <OPTIONAL DOMAIN>
      serverURL: "https://yourtenantname.secretservercloud.com"
      username:
        value: "yourusername"
      password:
        secretRef:
          name: <NAME_OF_K8S_SECRET>
          key: <KEY_IN_K8S_SECRET>

Describe alternatives you've considered
There are none that I know of. Domain is required by our secret server.

Additional context
The domain parameter is supported in the tss-sdk-go module, it's just not included as an option in a SecretStore.