feat: Add a view for mentions (#3505)

- Added a new table mentions for saving user mentions
- Added a filter conversation_type in the API
- Added a view to see the mentions

app/models/user.rb

@@ -80,13 +80,14 @@ class User < ApplicationRecord
   has_many :messages, as: :sender
   has_many :invitees, through: :account_users, class_name: 'User', foreign_key: 'inviter_id', source: :inviter, dependent: :nullify
 
-  has_many :notifications, dependent: :destroy_async
+  has_many :custom_filters, dependent: :destroy_async
+  has_many :mentions, dependent: :destroy_async
+  has_many :notes, dependent: :nullify
   has_many :notification_settings, dependent: :destroy_async
   has_many :notification_subscriptions, dependent: :destroy_async
+  has_many :notifications, dependent: :destroy_async
   has_many :team_members, dependent: :destroy_async
   has_many :teams, through: :team_members
-  has_many :notes, dependent: :nullify
-  has_many :custom_filters, dependent: :destroy_async
 
   before_validation :set_password_and_uid, on: :create