Style the "ID" links with a visited-link color, in fuzzing crash/results tables, so that you can tell which entries you've looked at.

STR:
(1) Visit https://fuzzmanager.fuzzing.mozilla.org/crashmanager/crashes/
(2) Click an entry in the first column (ID)
(3) Navigate back

EXPECTED RESULTS:
The link that you clicked should be a different color.

ACTUAL RESULTS:
The link is the same color as all the others.

This seems to be because we're styling them with

// Links
a {
  color: @link-color;
  text-decoration: none;

...in scaffolding.less, and we're not providing a different color in a :visited rule.

(Note, @link-color seems to be a LESS variable, which ends up as color: #337ab7; in the actual CSS. I'm not sure where it's defined, and I don't know LESS particularly well. But presumably this section of scaffolding.less is where we would want to define a :visited style for these links, and we'd want to define the color in the same spot where @link-color is defined.)

Reproduce the behavior at the crash manager crashes page by opening an ID link and navigating back. Inspect scaffolding.less and locate the definition of @link-color, then verify that the crash/results table ID links show a distinct visited color while preserving the existing link styling.