Fix setting task run mode in Edit Runtime

[MetRonnie]

PR against cylc#6039

[MetRonnie]

FAO @oliver-sanders

[oliver-sanders]

Is the graphene.Enum back to front per-chance?

[MetRonnie]

No, the Enum works correctly as far as creating the dropdown and sending the result back

This is because the Edit Runtime form is built from the result of querying the runtime of the task proxy:

class Runtime(ObjectType):
    ...
    run_mode = TaskRunMode(default_value=TaskRunMode.Live.name)

The problem is that in the mutation it sends back, there is no longer any association with this Enum, all you get is List(BroadcastSetting) which is the same as List(GenericScalar)

class Broadcast(Mutation):
    ...
    class Arguments:
        ...
        settings = graphene.List(
            BroadcastSetting,
            description=sstrip('''
                The `[runtime]` configuration to override with this broadcast
                (e.g. `script = true` or `[environment]ANSWER=42`).
            '''),

[oliver-sanders]

(sorry, was slow on the uptake there)

[MetRonnie]

I think this is actually easier than making the Enum name lowercase and sentence-casing it in the UI; the form generator code in the UI is difficult to work with and could do with a refactor at some point

[MetRonnie]

@wxtim