Zombie fields are not truly deleted, but stay in the data structure and can resurface

[kayaulai]

Zombie fields are not truly deleted in Rezonator. They are deleted from the interface, but remain in the data structure. When a tagset is saved as tag.json and loaded again, it can resurface, and when importing to rezonateR, it remains. This has been creating some issues in rezonateR import, when it affects important columns and I've had to find some hackish workarounds for now.

Example: the mistakenly named 'nonFragmentMember ' (with a trailing space) in this file: three-luckydreamalt-8296.zip

Removing a field should entail:

1. The field should be removed from the tag map.
2. The field and its value should be removed from every chain/entry/unit/etc.
3. A popup should appear to warn the user that they're about to remove an annotation from (number of lines) lines/