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.Core/Database/views.sql

@@ -0,0 +1,29 @@
+create view system_last_switch as
+select systems.id as system,
+       last_switch.id as switch,
+       last_switch.timestamp as timestamp,
+       array(select member from switch_members where switch_members.switch = last_switch.id) as members
+from systems
+    inner join lateral (select * from switches where switches.system = systems.id order by timestamp desc limit 1) as last_switch on true;
+
+create view member_list as
+select members.*,
+       -- Find last message ID
+       (select max(messages.mid) from messages where messages.member = members.id) as last_message,
+       
+       -- Find last switch timestamp
+       (
+           select max(switches.timestamp)
+           from switch_members
+                    inner join switches on switches.id = switch_members.switch
+           where switch_members.member = members.id
+       ) as last_switch_time,
+       
+       -- Extract month/day from birthday and "force" the year identical (just using 4) -> month/day only sorting! 
+       case when members.birthday is not null then
+           make_date(
+               4,
+               extract(month from members.birthday)::integer,
+               extract(day from members.birthday)::integer
+           ) end as birthday_md
+from members;