NEW Extend new AbstractGridFieldComponent class

[GuySartorelli]

This makes the GridFieldSortableRows component Injectable, and allows any future enhancements in the new abstract class to automatically apply without requiring additional changes in this module.

The class is introduced in silverstripe/framework 4.11.0 (see silverstripe/silverstripe-framework#10204) so the dependency constraint needs to be updated.

Some whitespace issues have also been fixed automatically by my IDE.

[GuySartorelli]

Note that tests will error until a 4.11 branch or tag is available in silverstripe/silverstripe-framework

[UndefinedOffset]

Thanks @GuySartorelli I'll merge this after I do #135, the tests ironically are broken at the moment anyways because this repo was using travis-ci.org which of course is now defunct. I've been using GitHub Actions quite a bit for work with @webbuilders-group and it's been quite good so I'm probably going to switch the repo over to that first before I merge this.

[UndefinedOffset]

Ok tests are now running on GitHub Actions, I'm going to hold on this for now until the 4.11 release is out then I'll merge this and tag likely as 3.0.0 (adjusting builds accordingly) as this is a breaking change.

[GuySartorelli]

Makes sense! Not sure how it breaks BC (unless someone has code that relies on GridFieldSortableRows not being injectable or not having a superclass?) but any release is better than no release. Thanks for letting me know :)

[emteknetnz]

@UndefinedOffset this isn't a breaking change, you shouldn't need to release a new major

Though yes, you will need to hold off until framework 4.11.0 has been released

[UndefinedOffset]

Tagged as 2.1.0, thanks!