Make .jsonc icon use storage icon (#6972)

Jsonc is a simplified json format which allows comments and unquoted
values delimited by whitespace. A jsonc formatted file can be
unambiguously transformed to a json file. Comments will be stripped out
and quotes added.

Release Notes:

- Added an icon for .jsonc files

assets/icons/file_icons/file_types.json

@@ -53,6 +53,7 @@
         "jpg": "image",
         "js": "code",
         "json": "storage",
+        "jsonc": "storage",
         "ldf": "storage",
         "lock": "lock",
         "log": "log",