IO-1551 Refactor messaging.

hasura/migrations/1638838165307_alter_table_public_conversations_add_column_unreadcnt/down.sql

@@ -0,0 +1,4 @@
+-- Could not auto-generate a down migration.
+-- Please write an appropriate down migration for the SQL below:
+-- alter table "public"."conversations" add column "unreadcnt" numeric
+--  not null default '0';

hasura/migrations/1638838165307_alter_table_public_conversations_add_column_unreadcnt/up.sql

@@ -0,0 +1,2 @@
+alter table "public"."conversations" add column "unreadcnt" numeric
+ not null default '0';