Improve Mount Wizard form performance

Follow-up

The following discussion from !385 (merged) should be addressed:

• @tobias.kuhnert started a discussion: (+3 comments)

  @nils.brinckmann can this be merged?

Description

• If you make changes in the mount wizard, especially in step 4 add mount information the form performs very slow.

Probable reason

• Every time the form changed all forms get validated