feat: Add support for multi-language support for Captain (#11068)

This PR implements the following features

- FAQs from conversations will be generated in account language
- Contact notes will be generated in account language
- Copilot chat will respond in user language, unless the agent asks the
question in a different language

## Changes
### Copilot Chat

- Update the prompt to include an instruction for the language, the bot
will reply in asked language, but will default to account language
- Update the `ChatService` class to include pass the language to
`SystemPromptsService`

### FAQ and Contact note generation

- Update contact note generator and conversation generator to include
account locale
- Pass the account locale to `SystemPromptsService`


<details><summary>Screenshots</summary>

#### FAQs being generated in system langauge

![CleanShot 2025-03-12 at 13 32
30@2x](https://github.com/user-attachments/assets/84685bd8-3785-4432-aff3-419f60d96dd3)


#### Copilot responding in system language

![CleanShot 2025-03-12 at 13 47
03@2x](https://github.com/user-attachments/assets/38383293-4228-47bd-b74a-773e9a194f90)


</details>

---------

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

spec/models/account_spec.rb

@@ -108,4 +108,30 @@ RSpec.describe Account do
       expect(ActiveRecord::Base.connection.execute(query).count).to eq(0)
     end
   end
+
+  describe 'locale' do
+    it 'returns correct language if the value is set' do
+      account = create(:account, locale: 'fr')
+      expect(account.locale).to eq('fr')
+      expect(account.locale_english_name).to eq('french')
+    end
+
+    it 'returns english if the value is not set' do
+      account = create(:account, locale: nil)
+      expect(account.locale).to be_nil
+      expect(account.locale_english_name).to eq('english')
+    end
+
+    it 'returns english if the value is empty string' do
+      account = create(:account, locale: '')
+      expect(account.locale).to be_nil
+      expect(account.locale_english_name).to eq('english')
+    end
+
+    it 'returns correct language if the value has country code' do
+      account = create(:account, locale: 'pt_BR')
+      expect(account.locale).to eq('pt_BR')
+      expect(account.locale_english_name).to eq('portuguese')
+    end
+  end
 end