chat items (#223)

* add chat items migration

* chat and chat items types

* queries draft

* ChatInfo with optional ChatItem

* schema adjustments

* flat schema and queries

* refactor ChatResponse using ChatItem types

* schema adjustments

* refactor GroupInfo to include GroupMember of the user

* remove Message

* createNewChatItem, sendDirectChatItem

* refactor to use GroupInfo in Chat type and all ChatResponses

* replace ContactName with Contact in some ChatResponse constructors

* remove Group selectors

* minor correction

* refactor

* refactor 2

* nullable created_by_msg_id

* remove normalized schema and queries

* ON DELETE CASCADE / SET NULL

* CIContent to Text

* files chat_item_id

* fix

* apply ciContentToText

* queries folder

* refactor

* moar refactor

Co-authored-by: Evgeny Poberezkin <2769109+epoberezkin@users.noreply.github.com>

simplex-chat.cabal

@@ -26,6 +26,7 @@ library
       Simplex.Chat.Messages
       Simplex.Chat.Migrations.M20220101_initial
       Simplex.Chat.Migrations.M20220122_pending_group_messages
+      Simplex.Chat.Migrations.M20220125_chat_items
       Simplex.Chat.Mobile
       Simplex.Chat.Options
       Simplex.Chat.Protocol