In the transaction split editor the tags column is designed similar
to categories and shows the assigned tags as text.
On editing a split a drop down box with all available tags and
checkboxes for removing assigned tags are visible.
It is intended to have tags on transaction and splits. Both can be
filtered by the ledger view filter line.
Please note that the report engine is not able to filter
tags on categories yet.
Ported to KF5 from commit c712d81154ef2fd5bb136bc4521ba3d046b74ba6.