[chore] Convert some settings / admin panel JS to TypeScript (#2247)

* initial conversion of STUFF to typescript

* more stuff

* update babel deps, include commonjs transform

* update bundler & eslint configuration

* eslint --fix

* upgrade deps

* update docs, build stuff, peripheral stuff

---------

Co-authored-by: f0x <f0x@cthu.lu>

web/source/settings/lib/form/get-form-mutations.js

@@ -17,8 +17,6 @@
 	along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-"use strict";
-
 const syncpipe = require("syncpipe");
 
 module.exports = function getFormMutations(form, { changedOnly }) {