Running FastCS demo against the sim fails due to GraphQL transport error

I've encountered problems running up the FastCS demo - the sim launches fine, but 'Temp Controller FastCS' crashes when it tries to make the Strawberry Schema, complaining about
`Unexpected type ''`

Fuller error message:

```
│ /cache/venv-for/scratch/fmq68384/code/FastCS/lib/python3.11/site-packages/graphql/type/definition.py:837 in fields │
│ │
│ 834 │ │ │ fields = resolve_thunk(self._fields) ╭────────────── locals ──────────────╮ │
│ 835 │ │ except Exception as error: │ self = │ │
│ 836 │ │ │ cls = GraphQLError if isinstance(error, GraphQLError) else TypeError ╰────────────────────────────────────╯ │
│ ❱ 837 │ │ │ raise cls(f"{self.name} fields cannot be resolved. {error}") from error │
│ 838 │ │ if not isinstance(fields, Mapping) or not all( │
│ 839 │ │ │ isinstance(key, str) for key in fields │
│ 840 │ │ ): │
╰─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯
TypeError: Query fields cannot be resolved. Unexpected type ''
```

Gary gave me a workaround which is to comment out the GraphQL transport in controller.yaml. ie.

```
# yaml-language-server: $schema=schema.json
controller:
ip_settings:
ip: "localhost"
port: 25565
num_ramp_controllers: 4
transport:
# - graphql:
# host: localhost
# port: 8083
# log_level: info
- epicsca:
pv_prefix: GARYDEMO
gui:
title: Temperature Controller Demo
output_path: ./demo.bob
```

but this needs addressing properly as the graphql transport should work

## Acceptance Criteria

Able to run up the FastCS demo against the sim without needing to comment out the graphql transport