R1:bd4ce3580ccf

Fix inline highlight behaviors for Pholio

Summary:
Some recent CSS change tweaked these out a bit. They were also sort of weird looking after fixing the double-draw thing:

- Make them work properly;
- make the implementation a bit simpler;
- make them clearer visually.

Also fix a bug where "border" and "fill" were accidentally reversed.

Test Plan:
{F34625}

(The highlight on the reticle is a little hard to pick out in the screenshot, but very obvious in practice.)

Reviewers: chad

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