Too many refactors in one:

- Allowed adding ephemeral(ish) views and functions
- Moved message_count to a concrete database field
- Moved most proxy logic to a stored procedure
- Moved database files around and refactored schema manager

PluralKit.Bot/Proxy/ProxyMatch.cs

@@ -5,10 +5,10 @@ namespace PluralKit.Bot
 {
     public struct ProxyMatch
     {
-        public PKMember Member;
+        public ProxyMember Member;
         public string? Content;
         public ProxyTag? ProxyTags;
-
+        
         public string? ProxyContent
         {
             get