fix: Update validations for filter service (#8239)

- Refactor filter service for better readability and maintenance
- Add validations for the following:
   - If an invalid attribute is passed, a custom exception InvalidAttribute will be thrown.
   - If an invalid operator is passed, a custom exception InvalidOperator will be thrown.
   - If an invalid value (currently checking only null check), a custom exception InvalidValue will be thrown.

Fixes: https://linear.app/chatwoot/issue/CW-2702/activerecordstatementinvalid-pginvalidtextrepresentation-error-invalid
Fixes: https://linear.app/chatwoot/issue/CW-2703/activerecordstatementinvalid-pginvaliddatetimeformat-error-invalid
Fixes:  https://linear.app/chatwoot/issue/CW-2700/activerecordstatementinvalid-pgsyntaxerror-error-syntax-error-at-or


Co-authored-by: Sojan <sojan@pepalo.com>

app/controllers/api/v1/accounts/conversations_controller.rb

@@ -44,6 +44,10 @@ class Api::V1::Accounts::ConversationsController < Api::V1::Accounts::BaseContro
     result = ::Conversations::FilterService.new(params.permit!, current_user).perform
     @conversations = result[:conversations]
     @conversations_count = result[:count]
+  rescue CustomExceptions::CustomFilter::InvalidAttribute,
+         CustomExceptions::CustomFilter::InvalidOperator,
+         CustomExceptions::CustomFilter::InvalidValue => e
+    render_could_not_create_error(e.message)
   end
 
   def mute