feat: rework group list into member list

PluralKit.Core/Database/Migrations/25.sql

@@ -0,0 +1,7 @@
+-- schema version 25
+-- group name privacy
+
+alter table groups add column name_privacy integer check (name_privacy in (1, 2)) not null default 1;
+alter table groups add column metadata_privacy integer check (metadata_privacy in (1, 2)) not null default 1;
+
+update info set schema_version = 25;