feat: add Google Email fetch and OAuth token refresh service (#9603)

This PR adds the following changes

1. Add `Imap::GoogleFetchEmailService` and
`Google::RefreshOauthTokenService`. The
`Google::RefreshOauthTokenService` uses
`OmniAuth::Strategies::GoogleOauth2` which is already added as a packge
2. Update `Inboxes::FetchImapEmailsJob` to handle Google inboxes
3. Add SMTP settings for Google in `ConversationReplyMailerHelper` to
allow sending emails


## Preview

#### Incoming emails

![CleanShot 2024-06-06 at 17 17
22@2x](https://github.com/chatwoot/chatwoot/assets/18097732/9d7d70d1-68e3-4c16-b1ca-e5a2e6f890e8)

#### Outgoing email

![CleanShot 2024-06-06 at 17 18
05@2x](https://github.com/chatwoot/chatwoot/assets/18097732/1b4abf0e-e311-493e-bdc8-386886afbb25)

---------

Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>

app/mailers/conversation_reply_mailer_helper.rb

@@ -14,6 +14,7 @@ module ConversationReplyMailerHelper
       @options[:bcc] = cc_bcc_emails[1]
     end
     ms_smtp_settings
+    google_smtp_settings
     set_delivery_method
 
     Rails.logger.info("Email sent from #{email_from} to #{to_emails} with subject #{mail_subject}")
@@ -23,23 +24,36 @@ module ConversationReplyMailerHelper
 
   private
 
-  def ms_smtp_settings
-    return unless @inbox.email? && @channel.imap_enabled && @inbox.channel.provider == 'microsoft'
+  def google_smtp_settings
+    return unless @inbox.email? && @channel.imap_enabled && @inbox.channel.google?
 
-    smtp_settings = {
-      address: 'smtp.office365.com',
+    smtp_settings = base_smtp_settings('smtp.gmail.com')
+
+    @options[:delivery_method] = :smtp
+    @options[:delivery_method_options] = smtp_settings
+  end
+
+  def ms_smtp_settings
+    return unless @inbox.email? && @channel.imap_enabled && @inbox.channel.microsoft?
+
+    smtp_settings = base_smtp_settings('smtp.office365.com')
+
+    @options[:delivery_method] = :smtp
+    @options[:delivery_method_options] = smtp_settings
+  end
+
+  def base_smtp_settings(domain)
+    {
+      address: domain,
       port: 587,
       user_name: @channel.imap_login,
       password: @channel.provider_config['access_token'],
-      domain: 'smtp.office365.com',
+      domain: domain,
       tls: false,
       enable_starttls_auto: true,
       openssl_verify_mode: 'none',
       authentication: 'xoauth2'
     }
-
-    @options[:delivery_method] = :smtp
-    @options[:delivery_method_options] = smtp_settings
   end
 
   def set_delivery_method
@@ -69,12 +83,12 @@ module ConversationReplyMailerHelper
     @inbox.inbox_type == 'Email' && @channel.imap_enabled
   end
 
-  def email_microsoft_auth_enabled
-    @inbox.inbox_type == 'Email' && @channel.provider == 'microsoft'
+  def email_oauth_enabled
+    @inbox.inbox_type == 'Email' && (@channel.microsoft? || @channel.google?)
   end
 
   def email_from
-    email_microsoft_auth_enabled || email_smtp_enabled ? channel_email_with_name : from_email_with_name
+    email_oauth_enabled || email_smtp_enabled ? channel_email_with_name : from_email_with_name
   end
 
   def email_reply_to