improvement: federation get_keys and optimize signingkey storage

- get encryption keys over federation
- optimize signing key storage
- rate limit parsing of bad events
- rate limit signature fetching
- dependency bumps

src/database.rs

@@ -213,7 +213,7 @@ impl Database {
             pusher: pusher::PushData::new(&db)?,
             globals: globals::Globals::load(
                 db.open_tree("global")?,
-                db.open_tree("servertimeout_signingkey")?,
+                db.open_tree("server_signingkeys")?,
                 config,
             )?,
             _db: db,