Add field settings

src/app/Settings.ts

@@ -0,0 +1,22 @@
+type FieldSetting = {
+  path?: string
+  name?: string
+  hidden?: boolean
+}
+
+export class Settings {
+  fields: FieldSetting[]
+
+  constructor(private local_storage: string) {
+    const settings = JSON.parse(localStorage.getItem(local_storage) ?? '{}')
+    if (!Array.isArray(settings.fields)) settings.fields = []
+    this.fields = settings.fields
+    this.save()
+  }
+
+  save() {
+    const settings = JSON.stringify({ fields: this.fields }) 
+    localStorage.setItem(this.local_storage, settings)
+    this.fields = [...this.fields.filter(v => v?.path), {}]
+  }
+}