Add new CSS, JS, and icon assets to rustfs-gui (#221)

* Add new CSS, JS, and icon assets to rustfs-gui

- Add `navbar.css` for styling the navigation bar.
- Add `sts.js` for handling tab switching and password toggling.
- Include new icon assets in `assets/icons` directory.
- Update `Dioxus.toml` to reference new assets.

* Remove unused icons from dioxus.toml

- Remove `assets/icons/icon_*.png` from the icon list.

cli/rustfs-gui/assets/styling/navbar.css

@@ -0,0 +1,16 @@
+#navbar {
+  display: flex;
+  flex-direction: row;
+}
+
+#navbar a {
+  color: #ffffff;
+  margin-right: 20px;
+  text-decoration: none;
+  transition: color 0.2s ease;
+}
+
+#navbar a:hover {
+  cursor: pointer;
+  color: #ffffff; // #91a4d2;
+}