NEW FEATURE: filter for variable names

[tobstac]

Summary

Add a possibility to filter the amount of variables shown in the variable field at the bottom of the window using variable names.

Reason

Some datasets can contain huge amounts of data fields (e.g. ICON output) and it can be a pain to try and scroll through the list to find the set of variables one is actually interested in.

Examples

I would like to see an additional text box close to the variable field where one can start typing parts of a variable name and then only variables which contain this text are shown below.

Thanks and best regards!