in a few places icon classes are constructed from string constants,
and those not always include the `ti` prefix
also updated the `grep` in `CONTRIBUTING.md` to catch those kind of
constants.
phopshor doesn't have anything decent for "folder symlink", the
"folder dashed" I picked is pretty bad
the three classes not prefixed with `ti ` are inside a conditional in
`packages/frontend/src/pages/admin/abuse-report/notification-recipient.item.vue`
I thought that `ti-fw` was mostly useless, but it turns out that:
- it affects the alignment of icons in many places
- it's set separately in some places
(e.g. `packages/frontend/src/ui/_common_/navbar.ts` has `<i
class="ti-fw" :class="[$style.itemIcon,
navbarItemDef[item].icon]"></i>`)
so we have to keep it around.
