Split each query and mutation into its own file, enhance return types

[rtman]

Description

Return types for graphql api queries/mutations should return standard responses:

Sucess:

ok: true,
body: SuccessResult

Fail:

ok: false,
error: {
   message: string
}

In order to do this there needs to be a type for each query/mutation that defines its return types. Best to split them into individual files for this, its better this way anyways as the files are quite long and complex already.

[rtman]

see subscription for implementation for one query