feat: improve config UI (#69)

* add first concept

* completed configuration ui update

* add button for testing email configuration

* improve mobile layout

* add migration

* run formatter

* delete unnecessary modal

* remove unused comment

frontend/src/utils/string.util.ts

@@ -0,0 +1,10 @@
+export const configVariableToFriendlyName = (variable: string) => {
+  return variable
+    .split("_")
+    .map((word) => word.charAt(0).toUpperCase() + word.slice(1).toLowerCase())
+    .join(" ");
+};
+
+export const capitalizeFirstLetter = (string: string) => {
+  return string.charAt(0).toUpperCase() + string.slice(1);
+};