Campaign Properties "import predefined" provides bad UX

[Azhrei]

Describe the bug
There are no tooltips for the bottom row of buttons on the Campaign Properties' Token Properties tab. This leads to a GM potentially wiping out configuration changes without warning.

To Reproduce
Steps to reproduce the behavior:

1. Go to Edit > Campaign Properties
2. Click on "Import predefined"
3. Without warning, all campaign properties are replaced!

Expected behavior
Each button should have tooltips explaining the hazards of use (if any). The import buttons should add an "Are you sure?" prompt that explains that the contents of other tabs will be replaced by the operation. Ideally, the import should be a merge operation, not a replace, with anything that might conflict triggering failure and an explanation of which pieces conflicted.

MapTool Info

• Version: 1.5.14+

Additional context
Because there's no tooltip or warning, a GM could be entering data on multiple different tabs and then find the Import buttons and decide to try them. If they haven't exited and reopened the dialog yet, they completely erase their work and can't just hit "Cancel" to get it back.

Related to #221 (closed) and #1238 (still open).