software pages grouped by moduleclass

[shahzebsiddiqui]

It would be nice in addition to supported software https://easybuild.readthedocs.io/en/latest/version-specific/Supported_software.html#list-software to generate a page with all software grouped by moduleclass.

It would be sufficient to name all software that belong to a moduleclass instead of naming all easyconfigs. Since we have --show-default-moduleclasses we can first show all available module classes supported by easybuild and then list of all software by group.

It could be nice to have this option on command line maybe eb --list-software-by-moduleclass <moduleclass>.