Support Q-CTRL

[kt474]

Once the server side updates are ready we'll have to support Q-CTRL from the client side. Users will need to be able to indicate (and also save in their account options) they want to use Q-CTRL's primitives:

service = QiskitRuntimeService(channel="ibm_cloud", instance="...", channel_strategy="q-ctrl")

Requirements

• An option for users to select Q-Ctrl as the error mitigation strategy. This selection can also be saved as part of save_account().
• Raise an error if Q-Ctrl is selected but channel is not IBM Cloud.
• Q-Ctrl only support resilience_level=1, so the provider should issue a warning if a different level is used. A warning instead of an error to allow users to switch between Q-Ctrl and regular without code change.

[jyu00]

Q-Ctrl only support resilience_level=1, so the provider should issue a warning if a different level is used. A warning instead of an error to allow users to switch between Q-Ctrl and regular without code change.

Let's hold off on this. There's discussion on whether Q-Ctrl should handle this.