feat: Improve CSAT responses (#11485)

# Pull Request Template

## Description

This PR introduces basic customization options for the CSAT survey:

* **Display Type**: Option to use star ratings instead of emojis.
* **Message Text**: Customize the survey message (up to 200 characters).
* **Survey Rules**: Send surveys based on labels — trigger when a
conversation has or doesn't have a specific label.

Fixes
https://linear.app/chatwoot/document/improve-csat-responses-a61cf30e054e

## Type of change

- [x] New feature (non-breaking change which adds functionality)

## How Has This Been Tested?

### Loom videos

**Website Channel (Widget)**

https://www.loom.com/share/7f47836cde7940ae9d17b7997d060a18?sid=aad2ad0a-140a-4a09-8829-e01fa2e102c5

**Email Channel (Survey link)**

https://www.loom.com/share/e92f4c4c0f73417ba300a25885e093ce?sid=4bb006f0-1c2a-4352-a232-8bf684e3d757

## Checklist:

- [x] My code follows the style guidelines of this project
- [x] I have performed a self-review of my code
- [x] I have commented on my code, particularly in hard-to-understand
areas
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged and published in downstream
modules

---------

Co-authored-by: Pranav <pranavrajs@gmail.com>

app/javascript/survey/components/Banner.vue

@@ -24,7 +24,7 @@ export default {
       class="ion-checkmark-circled text-3xl text-green-500 mr-1"
     />
     <i v-if="showError" class="ion-android-alert text-3xl text-red-600 mr-1" />
-    <label class="text-base font-medium text-black-800 mt-4 mb-4">
+    <label class="text-base font-medium text-n-slate-12 mt-4 mb-4">
       {{ message }}
     </label>
   </div>

app/javascript/survey/components/Feedback.vue

@@ -32,7 +32,7 @@ export default {
 
 <template>
   <div class="mt-6">
-    <label class="text-base font-medium text-black-800">
+    <label class="text-base font-medium text-n-slate-12">
       {{ $t('SURVEY.FEEDBACK.LABEL') }}
     </label>
     <TextArea