chore: move migrations to rust

also adds some basic test seed data

crates/migrate/data/seed.sql

@@ -0,0 +1,8 @@
+-- example data (for integration tests or such)
+
+insert into systems (hid, token) values (
+	'exmpl',
+	'vlPitT0tEgT++a450w1/afODy5NXdALcHDwryX6dOIZdGUGbZg+5IH3nrUsQihsw'
+);
+insert into system_config (system) values (1);
+insert into system_guild (system, guild) values (1, 466707357099884544);