Auto button for loader `rotation_angles` parameter sets value incorrectly

[yousefmoazzam]

The typescript type used to represent the rotation_angles parameter of the loader is not quite correct regarding where the auto should be placed. The type has this: https://github.com/DiamondLightSource/TomoHub/blob/1bc40efd239fd37e575970a062e9dea8bea53f2f/frontend/src/contexts/LoaderContext.tsx#L15-L21

but the auto should be for the entire rotation_angles field, not the data_path subfield.

Ie, the type should look something like this instead:

  rotation_angles: {
    data_path?: string
    user_defined?: {
      start_angle: number;
      stop_angle: number;
      angles_total: number;
    }  | "auto" | null; // Allow null and 'auto';

A consequence of the incorrect type is that when the auto toggle button in the Loader component is toggled on, this causes the rotation_angles parameter config to be this:

rotation_angles: {
  data_path: "auto"
}

which is incorrect, it should be:

rotation_angles: "auto"

This ultimately leads to a workflow triggered with the auto button toggled on to fail, because httomo is given an incorrect configuration of the rotation_angles parameter.