[RFE] sync to behave nicer with temp-containers

[vbatts]

• Multi-Account Containers Version: 8.0.7
• Operating System + Version: debian bullseye
• Firefox Version: 91.8.0esr-1~deb11u1
• Other installed Add-ons + Version + Enabled/Disabled-Status: temporary containers v1.9.2

Actual behavior

Setup: using firefox from multiple desktops, all with sync'ed profile and sync'ed containers, and with the add-ons of Multi-account-containers and https://github.com/stoically/temporary-containers.

On every new machine I configure firefox and container sync, it installs all containers, including those tmp containers already deleted from other machines. (>2000 containers)

The M-A-C menu becomes sluggish to respond with this many containers.

Further, attempting to delete these tmp containers from this fresh install takes a couple hours. Sitting at the about:preferences#containers page, clicking delete one a time. This page too is sluggish with this many containers

Expected behavior

Maybe:

• a pattern to tell container sync to not sync ^tmp[[:digit:]]* containers
• a management page to purge the containers to be sync'ed
• allow selecting multiple containers at a time to delete in bulk from about:preferences#containers

Steps to reproduce

1. use M-A-C and temp containers from more than one desktop, and have container sync
2. install a new firefox and sync the containers
3. try to delete or manage the containers

Notes

similar to #2076
updated: found stoically/temporary-containers#371 already pinned on their repo

[dannycolin]

Fixed by #2231.