Add redis caching to getting user notifications and projects [MOD-540] (#723)

* Add redis caching to getting a user's project ids

* Run `cargo sqlx prepare` to update the sqlx-data.json

* Add redis caching for getting user notifications

* Fix new clippy warnings

* Remove log that shouldn't have been committed

* Batch insert of notifications (untested)

* sqlx prepare...

* Fix merge conflict things and use new redis struct

* Fix bug with calling delete_many without any elements (caught by tests)

* cargo sqlx prepare

* Add tests around cache invalidation (and fix bug they caught!)

* Some test reorg based on code review suggestions

tests/common/asserts.rs

@@ -0,0 +1,3 @@
+pub fn assert_status(response: actix_web::dev::ServiceResponse, status: actix_http::StatusCode) {
+    assert_eq!(response.status(), status, "{:#?}", response.response());
+}