Feedback on Migration to aw-server-rust

Just made the move to aw-server-rust. Very impressed by the change. The transition went smoothly, and the queries are blazingly fast. When I used to wait maybe 30-40 seconds for a monthly review, it now takes 10 seconds. Congrats on a huge milestone for AW!

Couple of observations:

1. My previous db size was 264MB, and its now 213MB, that's an 8% decrease in size. I checked the logs, the bucket sizes and everything seems to match. Is a decrease of this size expected? Furthermore, does aw-server-rust use sqlite by default compared to peewee for aw-server?
2. Might be a good idea to put a notice for users to hard-refresh their page in the release notes once aw-server-rust becomes the default. Some of the buttons weren't responding for me and I was getting 404's. Only once I did a hard reset, did web-ui function correctly.
3. Some people may not be aware that aw-server and aw-server-rust store events in different databases(I definitely wasn't), so if they use them interchangeably they will lose some events. This obviously won't happen when aw-server-rust becomes the default, but in the meanwhile, possibly consider adding a disclaimer to the release

4. Looking at the logs, there seems to be an issue with sending events from firefox-watcher:

```
[2020-06-25][21:29:52][rocket::rocket][INFO] OPTIONS /api/0/buckets/aw-watcher-web-firefox/heartbeat?pulsetime=80:
[2020-06-25][21:29:52][_][INFO] Verifying origin: moz-extension://a8cf0cd0-2dad-427e-b3d0-ab9326727db2
[2020-06-25][21:29:52][_][INFO] Origin has a regex match? true
[2020-06-25][21:29:52][_][ERROR] No matching routes for OPTIONS /api/0/buckets/aw-watcher-web-firefox/heartbeat?pulsetime=80.
[2020-06-25][21:29:52][_][WARN] Responding with 404 Not Found catcher.
[2020-06-25][21:29:52][_][INFO] CORS Fairing: Turned missing route OPTIONS /api/0/buckets/aw-watcher-web-firefox/heartbeat?pulsetime=80 into an OPTIONS pre-flight request
[2020-06-25][21:29:52][_][INFO] Response succeeded.
[2020-06-25][21:29:52][rocket::rocket][INFO] POST /api/0/buckets/aw-watcher-web-firefox/heartbeat?pulsetime=80 application/json; charset=utf-8:
[2020-06-25][21:29:52][_][INFO] Verifying origin: moz-extension://a8cf0cd0-2dad-427e-b3d0-ab9326727db2
[2020-06-25][21:29:52][_][INFO] Origin has a regex match? true
[2020-06-25][21:29:52][_][INFO] Matched: POST /api/0/buckets//heartbeat? (bucket_events_heartbeat)
[2020-06-25][21:29:52][_][INFO] Outcome: Success
[2020-06-25][21:29:52][_][INFO] Response succeeded.
```

Logs for Chrome look to be fine.
System: Fedora 32, Firefox 77.0.1(most up to date)