FUI modal should be generated from php only

[mvorisek]

Currently there are two locations where FUI modal is generated without php:

https://github.com/atk4/ui/blob/8a359e0975/js/src/JqueryPlugin/ConfirmPlugin.js and https://github.com/atk4/ui/blob/8a359e0975/js/src/JqueryPlugin/CreateModalPlugin.js

If there should be no roundtrip between client and server, they can be pregenerated, but never constructed within js only.

[mvorisek]

As the JS calls should be coded from PHP only, I belive we should introduce something like "named JS code". We should however name it implicitly by its hash and ship it to the client only once.