ENH: Save/Cancel Pending Changes to Tag Group

[zdomke]

Description

Add a draft state to the Tag Group Dialog that allows users to cancel any pending changes to the group. This prevents any changes to the backend until the user clicks the save button.

Changes kept in a draft state include:

• Changing the tag group's name or description
• Adding tags to the group
• Deleting tags from the group
• Editing a tag's name or description

Motivation

Closes #24

Where Has This Been Documented?

Waiting on #7

Screenshots

Save button disabled if no changes or no title

Notify users of edits to Tag Group and enable "+ Add" button when applicable

Notify users of edits to tags

Pre-merge checklist

• Code works interactively
• Code follows the style guide
• Code contains descriptive docstrings

[zdomke]

Just remembered a question I had before. What is the best way to display tags that will be deleted?
Right now it is non-obvious what changes are expected to take place. See example where a tag is pending deletion.

Should I add a separate list of pending deletions under the list of tags?

• If I do this, should I move added tags & edited tags to their own lists as well?

Should I change the color/tooltip of the "unsaved changes" icon? (red)

• If I do this should I change the color of the icon for added tags as well? (green)