Attempt graphql backend

[marcelldls]

An additional "backend" for FastCS which provides a GraphQL api.
The API is fully discoverable and demoable from the autogenerated "GraphiQL gui" at "{domain}/graphql".
I choose to use the FastAPI "Strawberry" integration as it is the recommended library by FastAPI.

The following considersations have been taken to conform with best practices:

• Attributes to be read using a query (also demonstates how subcontrollers are nested)

Example:

Query request:
query{
    DesiredPosition
    subcontroller {
        DesiredPosition
    }
}

Query response:
{
  "data": {
    "subcontroller": {
      "DesiredPosition": 1.0,
    }
    "DesiredPosition": 1.0,
  }
}

• Attributes to be written using a mutation

Example:

Mutation request:
mutation{
  DesiredPosition(value: 2.0)
}

Mutation response:
{
  "data": {
    "DesiredPosition": 2.0
  }
}

• Commands can cause server side effects so they are triggered using a mutation as per convention
  • A boolean response is returned to confirm the command was executed successfully

Example:

Mutation request:
mutation{
  BlinkLED
}

Mutation response:
{
  "data": {
    "BlinkLED": true
  }
}

Further:

• I follow a similar pattern to the Tango "backend" to create the server and testing, so any feedback from the exisiting PRs should feed into this
• I have added nested subcontrollers to test arbitrary subcontroller nesting as this is a harder problem for the graphql request structure - the tests of other backends should also apply this and need to be updated accordingly

[GDYendell]

I have a had a quick look, but I am going to ignore this until we iterate on and merge some of the other recent PRs first, as you suggest.

[marcelldls]

I have a had a quick look, but I am going to ignore this until we iterate on and merge some of the other recent PRs first, as you suggest.

Lets do that. When we are done iterating, we can enjoy some of the graph recursion xD