add a warning before push and pull sync message and backup remote file

[test-0-zero]

Is your feature request related to a problem? Please describe.

I use google drive to store the bookmark sync file.

if I forgot the pull sync setting and I lose all the work done before the last sync

Describe the solution you'd like

• a warning message before Pull and Push synchronization
• a remote file backup (to be set separately the mode e.g. timestamp, name, location, etc.)

Describe alternatives you've considered

remote backup is a good idea to limit the damage caused by errors, which are propagated to all profiles and shared folders.