Change filesystem navigator into a class with a svelte store implementation

svelte/src/filesystem/edit_window/EditWindow.svelte

@@ -9,7 +9,7 @@ import SharingOptions from "./SharingOptions.svelte";
 
 let dispatch = createEventDispatcher()
 
-export let fs_navigator
+export let nav
 let file = {
 	path: "",
 	name: "",
@@ -117,9 +117,9 @@ const save = async (keep_editing = false) => {
 	}
 
 	if (open_after_edit) {
-		fs_navigator.navigate(file.path, false)
+		nav.navigate(file.path, false)
 	} else {
-		fs_navigator.reload()
+		nav.reload()
 	}
 
 	if (keep_editing) {
@@ -149,7 +149,7 @@ const save = async (keep_editing = false) => {
 	<div class="tab_content">
 		{#if tab === "file"}
 			<FileOptions
-				fs_navigator={fs_navigator}
+				nav={nav}
 				bind:file
 				bind:new_name
 				bind:visible