[FEATURE] Represent Selector as Component objects

[JakeQZ]

Part of #1325.

[coveralls]

coverage: 72.856% (+0.2%) from 72.628%
when pulling 30fcbe1 on feature/selector-representation
into dd1b3de on main.

[JakeQZ]

Would like initial feedback on this...

There's a bit more to do:

• A few more tests;
• Changelog entries.

It might be possible to break this down into seperate PR, but I can't think how - everything is interdependent.

[JakeQZ]

It might be possible to break this down into seperate PR, but I can't think how - everything is interdependent.

Perhaps an initial change would be to have setSelector() (and the constructor) throw an exception if the selector is invalid, using the existing isValid() method. I wouldn't consider this to be a breaking change, more of a fix, though something that would probably go in the 'Changed' section of the changelog.

[JakeQZ]

Perhaps an initial change would be to have setSelector() (and the constructor) throw an exception if the selector is invalid, using the existing isValid() method. I wouldn't consider this to be a breaking change, more of a fix, though something that would probably go in the 'Changed' section of the changelog.

#1498 covers exceptions possibly being thrown by setSelector() and the constructor.

[JakeQZ]

There's a bit more to do:

• A few more tests;
• Changelog entries.

Have added the additional tests and changelog entry.

[JakeQZ]

Have added the additional tests and changelog entry.

Now actually committed that update.

[JakeQZ]

#1499 partially implements getArrayRepresentation() to reduce the payload of this PR.

[JakeQZ]

I've tidied up a few things, and reduced the diff with a pre-PR. I can't see any other possible pre-PRs, so this is ready for re-review.

[oliverklee]

Looks very good! Only one nit.

[JakeQZ]

I spotted a few type annotations in SelectorTest that could be tightened to use non-empty-list or non-empty-string, so have done so, and added a fluent interface test.

[JakeQZ]

Also now corrected a @throws annotation.

[oliverklee]

Nice!