Support closures

[aschempp]

It should be possible to use closures (e.g. for wizard callback) like the Contao core does.

[garyee]

+1

[zonky2]

• load_callback - Hotfix add closure load_callback #230
• wizard - hotfix add closure wizard #236
• save_callback (table)
• save_callback (widget)

[zonky2]

@aschempp what is the "wizard callback"? => https://docs.contao.org/books/api/dca/callbacks.html

[aschempp]

It's a field configuration: https://docs.contao.org/books/api/dca/reference.html#fields