feat: css editor (#1542)

* feat: allow editing CSS from settings

---------

Co-authored-by: Carlos Valente <carlosvalente@pm.me>

refactor: style tweaks

apps/client/src/common/api/assets.ts

@@ -0,0 +1,30 @@
+import axios from 'axios';
+
+import { apiEntryUrl } from './constants';
+
+const assetsPath = `${apiEntryUrl}/assets`;
+
+/**
+ * HTTP request to get css contents
+ */
+export async function getCSSContents(): Promise<string> {
+  const res = await axios.get(`${assetsPath}/css`);
+  return res.data;
+}
+
+/**
+ * HTTP request to post css contents
+ */
+export async function postCSSContents(css: string): Promise<void> {
+  await axios.post(`${assetsPath}/css`, {
+    css,
+  });
+}
+
+/**
+ * HTTP request to restore default css
+ */
+export async function restoreCSSContents(): Promise<string> {
+  const res = await axios.post(`${assetsPath}/css/restore`);
+  return res.data;
+}