feat: add abuse handling

PluralKit.Core/Database/Migrations/44.sql

@@ -0,0 +1,23 @@
+-- database version 44
+-- add abuse handling measures
+
+create table abuse_logs (
+	id serial primary key,
+	uuid uuid default gen_random_uuid(),
+	description text,
+	deny_bot_usage bool not null default false,
+	created timestamp not null default (current_timestamp at time zone 'utc')
+);
+
+alter table accounts add column abuse_log integer default null references abuse_logs (id) on delete set null;
+create index abuse_logs_uuid_idx on abuse_logs (uuid);
+
+-- we now need to handle a row in "accounts" table being created with no
+-- system (rather than just system being set to null after insert)
+--
+-- set default null and drop the sequence (from the column being created
+-- as type SERIAL)
+alter table accounts alter column system set default null;
+drop sequence accounts_system_seq;
+
+update info set schema_version = 44;