quickFilters buttons don't work when dragging from customize toolbar

[RealRaven2000]

When dragging a button of quickFilters to the main toolbar it doesn't work at first - Thunderbird or quickFilters need to be restarted. This is caused by code that attaches the event handler to the buttons when quickFilters starts - but it only can do this if the buttons are already in the toolbar. This needs to be fixed so that the buttons work right away.

[RealRaven2000]

Below is a prerelease version that uses inline command handlers - these should always work, even when dragging in the buttons fresh from the toolbar palette (customize toolbar)

quickFilters-wx-5.9.1pre13.zip

As always, to install prereleases here from github, download the zip file and then drag it into Thunderbird Add-ons Manager - without extracting the contents. We are not allowed attaching xpi files but zip are essentially the same format with a different extension.

[RealRaven2000]

Fixed in 5.9.1 released on 09/04/2023 (April)