#43 removed the formatting of the tags

The tags of the taggroup 'Topic Category' are no longer formatted.
To display the Tag in the JLabel the usual binding is used.
Merge branch 'feature/43-not-format-topic-category' into dev
Both lists in AdditionalTagsPanel have the same width

In AdditionalTagsPanel, the GridLayout is used, such that the two lists
can use the same amount of space. This avoids an ugly jumping of the
GUI.