revert: reverts csrf-csrf back to csurf (#1442)

* revert: reverts csrf-csrf back to csurf

This reverts csrf-csrf change brought on by `9e3119` in #1393 back to `csurf` that is maintained

* fix: type declarations for csurf

server/types/custom.d.ts

@@ -0,0 +1,4 @@
+declare module '@dr.pogodin/csurf' {
+  import csrf = require('csurf');
+  export = csrf;
+}