add device message if quota is exceeding (#2621)

* resultify update_recent_quota()

* add a device-message if quota exceeds QUOTA_WARN_THRESHOLD_PERCENTAGE

* check if a quota warning should be added during housekeeping, this is at least once a day

* dc_get_config("quota_exceeding") is useful for bots

* make clippy happy

* reword QuotaExceedingMsgBody message

* avoid lots of warnings if quota jitters around the warning threshold

* allow clippy::assertions_on_constants

these constants depend on each other, it makes sense to check that they are not changed in an incompatible way

src/context.rs

@@ -423,6 +423,12 @@ impl Context {
                 .await?
                 .to_string(),
         );
+        res.insert(
+            "quota_exceeding",
+            self.get_config_int(Config::QuotaExceeding)
+                .await?
+                .to_string(),
+        );
 
         let elapsed = self.creation_time.elapsed();
         res.insert("uptime", duration_to_str(elapsed.unwrap_or_default()));