Add Vision Support (#889)

# Summary of Changes
* New UI to show preview of image uploads
* ChatML message changes to support gpt-4o vision based responses on images
* AWS S3 image uploads for persistent image context in conversations
* Database changes to have `vision_enabled` option in server admin panel while configuring models
* Render previously uploaded images in the chat history, show uploaded images for pending msgs
* Pass the uploaded_image_url through to subqueries
* Allow image to render upon first message from the homepage
* Add rendering support for images to shared chat as well
* Fix some UI/functionality bugs in the share page
* Convert user attached images for chat to webp format before upload
* Use placeholder to attached image for data source, response mode actors
* Update all clients to call /api/chat as a POST instead of GET request
* Fix copying chat messages with images to clipboard

TLDR; Add vision support for openai models on Khoj via the web UI!

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Co-authored-by: sabaimran <narmiabas@gmail.com>
Co-authored-by: Debanjum Singh Solanky <debanjum@gmail.com>

src/interface/web/app/share/chat/sharedChat.module.css

@@ -12,15 +12,11 @@ div.main {
 
 div.inputBox {
     border: 1px solid var(--border-color);
-    border-radius: 16px;
     margin-bottom: 20px;
     gap: 12px;
-    padding-left: 20px;
-    padding-right: 20px;
     align-content: center;
 }
 
-
 input.inputBox {
     border: none;
 }
@@ -31,7 +27,7 @@ input.inputBox:focus {
 }
 
 div.inputBox:focus {
-    box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
+    box-shadow: 0px 8px 16px 0px rgba(0, 0, 0, 0.2);
 }
 
 div.chatBodyFull {
@@ -94,7 +90,6 @@ div.agentIndicator {
     padding: 10px;
 }
 
-
 @media (max-width: 768px) {
     div.chatBody {
         grid-template-columns: 0fr 1fr;
@@ -124,5 +119,4 @@ div.agentIndicator {
         gap: 0;
         grid-template-columns: 1fr;
     }
-
 }