Implement support for icon themes

[raffaem]

Support icon themes and compile extension file for different icon themes.

Implements #43.

[adomasven]

As discussed in #43, we are not interested in icon themes for our extension if it means multiple extension files/builds. We applaud the effort that went into this, but word processor plugins, especially their installation is a common step of using Zotero that causes users issues and that we often have to help troubleshoot. We don't want to introduce any additional confusion or excessive choices for users when they face already frustrating situations where things don't work as they should.

Moreover, this repo and the main Zotero repo contains code to automatically install these extensions into LibreOffice and to keep them up to date when they are updated from our side. That code would need a rework before your approach for icon themes could realistically even be considered for merging.

We would love to support extension icon themes if they resided within a single LibreOffice extension and switched automatically when LibreOffice theme is switched, that way not introducing any user confusion or excessive code complexity for a nice-to-have. Since LibreOffice is open-source we welcome you to contribute to their project and add that feature, although I recognize that their codebase is quite opaque and may have too high a barrier of entry.

Otherwise, we welcome you to provide this as a fork for advanced users who are interested in icon themes despite additional complexity, although you will have to make sure the icon theme files are updated as we update the extension and icon theme users keep their plugins up to date too.

[rizmut]

Hi what a nice discussion. I am pretty agree with @adomasven reasoning, so I filed up a bug report in LibreOffice Bugzilla. Hopefully someone step in.