feat: Implement UI for Agent Bots in settings and remove CSML support (#11276)

- Add agent bots management UI in settings with avatar upload
- Enable agent bot configuration for all inbox types
- Implement proper CRUD operations with webhook URL support
- Fix agent bots menu item visibility in settings sidebar
- Remove all CSML-related code and features
- Add migration to convert existing CSML bots to webhook bots
- Simplify agent bot model and services to focus on webhook bots
- Improve UI to differentiate between system bots and account bots

## Video 





https://github.com/user-attachments/assets/3f4edbb7-b758-468c-8dd6-a9537b983f7d

---------

Co-authored-by: iamsivin <iamsivin@gmail.com>
Co-authored-by: Sivin Varghese <64252451+iamsivin@users.noreply.github.com>
Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>
Co-authored-by: Pranav <pranav@chatwoot.com>

app/models/agent_bot.rb

@@ -25,9 +25,8 @@ class AgentBot < ApplicationRecord
   has_many :inboxes, through: :agent_bot_inboxes
   has_many :messages, as: :sender, dependent: :nullify
   belongs_to :account, optional: true
-  enum bot_type: { webhook: 0, csml: 1 }
+  enum bot_type: { webhook: 0 }
 
-  validate :validate_agent_bot_config
   validates :outgoing_url, length: { maximum: Limits::URL_LENGTH_LIMIT }
 
   def available_name
@@ -51,9 +50,7 @@ class AgentBot < ApplicationRecord
     }
   end
 
-  private
-
-  def validate_agent_bot_config
-    errors.add(:bot_config, 'Invalid Bot Configuration') unless AgentBots::ValidateBotService.new(agent_bot: self).perform
+  def system_bot?
+    account.nil?
   end
 end