Add a dropdown for resource selection and adopt it in the 'Image' node (#4543)

* Add a dropdown for resource selection and adopt it in the Image node

* Route every image upload through a new ResourceUpload handler with desktop support and migrate wired 'Image' node inputs

* Show each resource's user count in the resource picker dropdown

* Send a picked resource file to the document that requested it, list every non-font resource in the picker, and link sibling message docs

desktop/wrapper/src/handle_desktop_wrapper_message.rs

@@ -22,6 +22,11 @@ pub(super) fn handle_desktop_wrapper_message(dispatcher: &mut DesktopWrapperMess
 			OpenFileDialogContext::Import => {
 				dispatcher.queue_desktop_wrapper_message(DesktopWrapperMessage::ImportFile { path, content });
 			}
+			OpenFileDialogContext::UploadResource => {
+				let name = path.file_name().map(|name| name.to_string_lossy().to_string());
+				let message = ResourceUploadMessage::ReceiveUpload { name, data: content.into() };
+				dispatcher.queue_editor_message(message);
+			}
 		},
 		DesktopWrapperMessage::SaveFileDialogResult { path, context } => match context {
 			SaveFileDialogContext::Document { document_id, content } => {

desktop/wrapper/src/intercept_frontend_message.rs

@@ -26,6 +26,14 @@ pub(super) fn intercept_frontend_message(dispatcher: &mut DesktopWrapperMessageD
 				context: OpenFileDialogContext::Import,
 			});
 		}
+		FrontendMessage::TriggerUploadResource { filters } => {
+			dispatcher.respond(DesktopFrontendMessage::OpenFileDialog {
+				title: "Select File".to_string(),
+				filters,
+				multiple: false,
+				context: OpenFileDialogContext::UploadResource,
+			});
+		}
 		FrontendMessage::TriggerSaveDocument {
 			document_id,
 			name,

desktop/wrapper/src/messages.rs

@@ -107,6 +107,7 @@ pub enum DesktopWrapperMessage {
 pub enum OpenFileDialogContext {
 	Open,
 	Import,
+	UploadResource,
 }
 
 pub enum SaveFileDialogContext {