Consider Which Functions Exposed To User / Top-Level Module

[AFg6K7h4fhy2]

As per this comment #35 (comment), there remains need for discussion on which functions within forecasttools-py are exposed to the user. These choices will guide error messaging and handling.

[AFg6K7h4fhy2]

From PR 35, we have DHM's comment:

Beyond the scope of this PR, but once this lands there should be a cleanup PR to remove these validation helpers from the top-level namespace. Even if they're going to be user-exposed, that's too prominent I think.

Pertaining to:

    idata_group = forecasttools.validate_and_get_idata_group(
        idata=idata, group=group
    )
    variable_data = forecasttools.validate_and_get_idata_group_var(
        idata_group=idata_group, group=group, variable=variable
    )
    forecasttools.validate_idata_group_var_dim(
        variable_data=variable_data, dimension=dimension
    )