core: support down migrations to allow reverting to the previous version (#2072)

* core: support down migrations to allow reverting to the previous version

* update schema

* update simplexmq

* rename errors

* remove unused functions

* migration UI, test migration

* update migration UI

* return current migrations in CRVersionInfo

* update simplexmq

* test down migrations

* cleanup ios

* show migrations in log

src/Simplex/Chat/Migrations/M20230317_hidden_profiles.hs

@@ -12,3 +12,11 @@ ALTER TABLE users ADD COLUMN view_pwd_hash BLOB;
 ALTER TABLE users ADD COLUMN view_pwd_salt BLOB;
 ALTER TABLE users ADD COLUMN show_ntfs INTEGER NOT NULL DEFAULT 1;
 |]
+
+down_m20230317_hidden_profiles :: Query
+down_m20230317_hidden_profiles =
+  [sql|
+ALTER TABLE users DROP COLUMN view_pwd_hash;
+ALTER TABLE users DROP COLUMN view_pwd_salt;
+ALTER TABLE users DROP COLUMN show_ntfs;
+|]

src/Simplex/Chat/Migrations/chat_schema.sql

@@ -1,6 +1,7 @@
 CREATE TABLE migrations(
   name TEXT NOT NULL,
   ts TEXT NOT NULL,
+  down TEXT,
   PRIMARY KEY(name)
 );
 CREATE TABLE contact_profiles(