Fix missing upload button (#2393)

The code snippet `input[type=file]{ display: none;}` was unintentionally hiding the upload button, to fix this, it was changed to only target input within `.input-container`

src/main/resources/static/css/fileSelect.css

@@ -84,7 +84,7 @@
   z-index: 2;
 }
 
-input[type="file"] {
+.input-container input[type="file"] {
   display: none;
 }