Export the new rules instead of all the rules

[kalbasit]

When I create a new filter, I always like to apply it to existing emails and since gmailctl does not support that, I have to import the filters in the UI. Importing the filters takes a long time so currently I have to export the rules and then manually edit the file to remove all existing rules to avoid creating duplicates on the UI. Can we add a flag (perhaps --new) to export only the new rules?

[mbrt]

Perhaps adding a --format option to the diff command could help here?

[github-actions]

This issue is stale because it has been open for 30 days without activity.
This will be closed in 7 days, unless you add the 'lifecycle/keep-alive' label or comment.

[kalbasit]

@mbrt do you mind adding the keep alive label? Thanks, and happy holidays.