Feature: Conversation Continuity with Email (#770)

* Added POC for mail inbox reply email
* created mailbox and migratuion for the same
* cleaned up sidekiq queues and added the queues for action mailbox and active storage
* created conversation mailbox and functionlaity to create a message on the conversation when it's replied

* Added UUID to conversation to be used in email replies

* added migration to add uuid for conversation
* changed parsing and resource fetching to reflect matching uuid and
  loading conversation alone
* cleaned up conversation mailbox.rb

* Added content type & attribute for message

* Added the new reply email to outgoing emails
* Added migration to accounts for adding domain and settings
* Modified seeds to reflect this changes
* Added the flag based column on account for boolean settings
* Added the new reply to email in outgoing conversation emails based on conditions

* Added dynamic email routing in application mailbox
* Added dynamic email routing in application mailbox
* Added a catch all deafult empty mailbox
* Added annotation for account

* Added the complete email details & attachments to the message
* Added the complete email details to the message in content_attributes, like subject, to, cc, bcc etc
* Modified the mail extractor to give a serilaized version of email
* Handled storing attachments of email on the message

* Added incoming email settings, env variables

* [#138] Added documentation regarding different email settings and variables

* Fixed the mail attachments blob issue (#138)
* Decoided attachments were strings and had to construct blobs out fo them to work with active storage
* Fixed the content encoding issue with mail body
* Fixed issue with Proc used in apllication mailbox routing
* Fixed couple of typos and silly mistakes

* Set appropriate from email for conversation reply mails (#138)
* From email was taken from a env variable, changed it to take from account settings if enabled
* Set the reply to email correctly based on conversation UUID
* Added commented config ind development.rb for mailbox ingress

* Added account settings for domain and support email (#138)
* Added the new attributes in accounts controller params whitelisting, api responses
* Added options for the the new fields in account settings

* Fixed typos in email continuity docs and warnings

* Added specs for conversation reply mailer changes (#138)
* Added specs for
  * conversation reply mailer
  * Accounts controller
  * Account and Conversation models

* Added tests for email presenter (#138)

* Specs for inbound email routing and mailboxes (#138)

app/models/message.rb

@@ -51,10 +51,11 @@ class Message < ApplicationRecord
     input_select: 4,
     cards: 5,
     form: 6,
-    article: 7
+    article: 7,
+    incoming_email: 8
   }
   enum status: { sent: 0, delivered: 1, read: 2, failed: 3 }
-  store :content_attributes, accessors: [:submitted_email, :items, :submitted_values], coder: JSON
+  store :content_attributes, accessors: [:submitted_email, :items, :submitted_values, :email], coder: JSON
 
   # .succ is a hack to avoid https://makandracards.com/makandra/1057-why-two-ruby-time-objects-are-not-equal-although-they-appear-to-be
   scope :unread_since, ->(datetime) { where('EXTRACT(EPOCH FROM created_at) > (?)', datetime.to_i.succ) }