Add options to sort/group builds table entries by attributes

[rajgoesout]

https://ports.macports.org/port/python37/builds

In the builds info table, there could be buttons to sort in ascending/desc order of buildno., start time, etc. Also an option to group the builds by builder, watcher, build status, etc. could be added.

[mascguy]

I'd love to see this too, as the list of builds can be quite lengthy. (And will be even more so, once our new macOS Monterey buildbots come online.)