Linking to particular comments or replies in reviews used to require

digging through the page to get the appropriate anchor name, which was

kind of terrible. The header/footer of reviews couldn't even be linked to.

This change aims to fix all this by introducing a couple UI enhancements

for linking.
The timestamps on entries and on replies are now anchors to their

particular locations, allowing one to right-click and copy the link.

This is a familiar concept for many, which is why it's included, but

it's not the primary means of linking, as it doesn't cover everything.

Top-level comments don't have individual timestamps, so it's not

suitable for those.
Instead, we offer a common way of linking to any comment or reply by

hovering over and clicking a link icon to the left of the review box.

This only shows on hover, keeping the UI largely clean, but making the

presence of the link obvious to users.
The "floating anchor" link is positioned such that a user can easily

move their mouse cursor from the comment/reply onto the link without it

disappearing. It covers the entire height of the comment/reply and

extends most of the way to the left of the page, with sufficient padding

around the icon itself to make it easy to hit.
This required a bit of element restructuring, as the comment and its

replies shared a parent container. Those are now split out into two

separate parents, retaining all the margins/padding that we had before,

but making it much easier to draft CSS rules that target exactly what we

need without hacks.
When linking to a comment or reply, we no longer wrap the text in a blue

box. This was kind of distracting and messed with the layout a bit.

Instead, we just use the standard browser behavior of scrolling to that

element. Highlighting of a selected comment may come back in a future

change in a different form, however, as I want to eventually add

keyboard navigation like the diff viewer has.

Tested hovering and the resulting links for all types of comments and

replies, in desktop and mobile mode.
Compared the padding/margins on the page with how things looked before

the restructuring/style changes.