Several more database-y refactors

- DbConnectionFactory renamed to "Database", will now be the primary entry point for DB stuff
- Created IPKConnection interface mostly containing async extensions to IDbConnection, use this going forward
- Reworked the Connection/Command wrappers (that have performance/logging extensions)
- Probably more stuff that I forgot???

PluralKit.Bot/Handlers/MessageEdited.cs

@@ -11,9 +11,9 @@ namespace PluralKit.Bot
     {
         private readonly LastMessageCacheService _lastMessageCache;
         private readonly ProxyService _proxy;
-        private readonly DbConnectionFactory _db;
+        private readonly Database _db;
 
-        public MessageEdited(LastMessageCacheService lastMessageCache, ProxyService proxy, DbConnectionFactory db)
+        public MessageEdited(LastMessageCacheService lastMessageCache, ProxyService proxy, Database db)
         {
             _lastMessageCache = lastMessageCache;
             _proxy = proxy;