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)

.env.example

@@ -8,7 +8,7 @@ FORCE_SSL=
 # api_only: disables the UI for signup, but you can create sign ups via the account apis
 ENABLE_ACCOUNT_SIGNUP= 
 
-#redis config
+# Redis config
 REDIS_URL=redis://redis:6379
 # If you are using docker-compose, set this variable's value to be any string,
 # which will be the password for the redis service running inside the docker-compose
@@ -22,7 +22,7 @@ POSTGRES_PASSWORD=
 RAILS_ENV=development
 RAILS_MAX_THREADS=5
 
-#mail
+# Mail outgoing
 MAILER_SENDER_EMAIL=accounts@chatwoot.com
 SMTP_PORT=1025
 SMTP_DOMAIN=chatwoot.com
@@ -34,20 +34,27 @@ SMTP_PASSWORD=
 SMTP_AUTHENTICATION=
 SMTP_ENABLE_STARTTLS_AUTO=
 
-#misc
+# Mail Incoming
+# Use one of the following based on the email ingress service
+# Ref: https://edgeguides.rubyonrails.org/action_mailbox_basics.html
+RAILS_INBOUND_EMAIL_PASSWORD=
+MAILGUN_INGRESS_SIGNING_KEY=
+MANDRILL_INGRESS_API_KEY=
+
+# Misc
 FRONTEND_URL=http://0.0.0.0:3000
 ACTIVE_STORAGE_SERVICE=local
 
-#s3
+# Amazon S3
 S3_BUCKET_NAME=
 AWS_ACCESS_KEY_ID=
 AWS_SECRET_ACCESS_KEY=
 AWS_REGION=
 
-#sentry
+# Sentry
 SENTRY_DSN=
 
-#Log settings
+# Log settings
 LOG_LEVEL=info
 LOG_SIZE=500 
 
@@ -61,7 +68,7 @@ FB_VERIFY_TOKEN=
 FB_APP_SECRET=
 FB_APP_ID=
 
-#twitter
+# Twitter
 TWITTER_APP_ID=
 TWITTER_CONSUMER_KEY=
 TWITTER_CONSUMER_SECRET=