Adds dummy modal weight input scene. Refs #27.
Exports weight access proc. Refs #27.
Fills picker values. Refs #27.
Implements addition of the selected value. Refs #27.
Documents task in changes log. Refs #27.
Removes old input tab. Refs #27.
Rewords changes log. Refs #27.
Merge branch 'feature/t27_merge_input_with_history'