Updating get_meta to handle 3-col info on filters and indicators

[rmbielby]

Brief overview of changes

The meta data returned by the API has been changed to include id, col_name and label for filter and indicator columns (where previously it was just col_name and label). This updates get_meta() to account for the change to the API behaviour.

Why are these changes being made?

Change in API behaviour

Detailed description of changes

I've updated parse_meta_filter_columns() to account for the extra column and to label them up appropriately in the returned meta data frame.

Bonus change: I originally wrote parse_meta_indicator_columns() for get_meta(), but realised that parse_meta_filter_columns() did an identical job, so never actually used it. I intended to go back and delete it before finishing get_meta() but must have forgotten, so done that now.

Also updated the tests to account for the change.

[cjrace]

One minor comment for somewhere else I think you need to update - should this be col_id rather than col_name?

[cjrace]

Possibly also a question for your next work on the tidying / swapping of ids to labels as to whether having both col_id and col_name would be helpful in the meta response for filter_items. It's not necessary, but could be nice for users, and might be helpful for some of the processing (or might not make a difference!)

[rmbielby]

One minor comment for somewhere else I think you need to update - should this be col_id rather than col_name?

Made that change now.

[rmbielby]

Possibly also a question for your next work on the tidying / swapping of ids to labels as to whether having both col_id and col_name would be helpful in the meta response for filter_items. It's not necessary, but could be nice for users, and might be helpful for some of the processing (or might not make a difference!)

Maybe, I could argue myself either way I think. Think I'd either keep it as it is or merge filter_columns and filter_items together as one single thing. Not keen on the halfway ground of the col_names being repeated in two different places though. At the moment, I feel like it's easy enough for a user to do a left join on col_id if they want everything together, so marginally favour keeping the status quo as it feels like the most efficient way of storing the info.