fix upload modal loses its content when closed

Remove key from `UploadContainer` that causes component data to be destroyed when modal is closed.
Also, `eventReset()` the modal when there is an "immediate" drag-drop upload.

client/src/components/Upload/DefaultBox.vue

@@ -113,15 +113,15 @@ const queue = new UploadQueue({
 });
 
 /** Add files to queue */
-function addFiles(files) {
+function addFiles(files, immediate = false) {
     if (!isRunning.value) {
+        if (immediate || !props.multiple) {
+            eventReset();
+        }
         if (props.multiple) {
             queue.add(files);
-        } else {
-            eventReset();
-            if (files.length > 0) {
-                queue.add([files[0]]);
-            }
+        } else if (files.length > 0) {
+            queue.add([files[0]]);
         }
     }
 }

client/src/components/Upload/UploadContainer.vue

@@ -112,7 +112,7 @@ const showRegular = computed(() => !props.formats || hasRegularExtension);
 const showRules = computed(() => !props.formats || props.multiple);
 
 function immediateUpload(files) {
-    regular.value?.addFiles(files);
+    regular.value?.addFiles(files, true);
 }
 
 function toData(items, history_id, composite = false) {

client/src/components/Upload/UploadModal.vue

@@ -86,7 +86,6 @@ defineExpose({
         <UploadContainer
             v-if="currentHistoryId"
             ref="content"
-            :key="showModal"
             :current-user-id="currentUser?.id"
             :current-history-id="currentHistoryId"
             v-bind="options"