[DevToolbar] Iterate on UI design

Mini tasks:

[ ] Ensure list item styles (height, font, layout, padding) are consistent for every panel
[x] Update panel headers style to match the design
- [x] left-aligned, project badge
- [x] header links to the relevant page
- [x] make sure same height + font
- [x] gray and bold "Unresolved issues/feedback related to this page" for those panels. Divider doesn't reach all the way across panel
- [x] also, remove the URL from the issues/feedback header, it should only say "this page"

[x] Feedback panel: change header button from "+" to "Report a bug" (see design)

[x] FF Panel: move clear overrides button from above search bar to the bottom of the "Overrides". Use x icon and "Remove all"
[x] FF Panel: make a "+ Add a Flag" button in header.
- does this replace the "Add override button" we currently have at the bottom?
[ ] FF Panel: make toggles larger(?)
- Contrary to the figma I think we should keep the true/false for clarity.
[x] FF Panel: remove the gray "Name Value" header
[x] FF Panel: "search flags" -> "search"

[x] Crash-free-rate numbers, release ver, and empty issue list encapsulated in boxes
[x] Add box color highlight (green/red) for crash-free-rate change
[x] Update empty state "No new issues in this release"

[ ] Replay/Web Vital/newer panels: brush up styles and ask Jesse for design thoughts

[ ] (andrew) By default, toolbar is just a single icon: Sentry logo
- [ ] The Sentry toolbar expands on onMouseEnter, and contracts onMouseExit if no panel is selected, or the pinning functionality isn’t active
[ ] (andrew) Sentry logo links to Sentry (replaces the X button)
[ ] (andrew) Button to toggle pinned state
[x] Alerts panel red number badge becomes a small red indicator dot
- [x] Should also update the styling of the badge added here https://github.com/getsentry/sentry/pull/75210
[ ] https://github.com/getsentry/sentry/issues/76251

getsentry / sentry