When using callback form functions, name and id field may not be correctly set

[TheWitness]

Describe the bug

When typing into a drop callback for host in say the Data Sources page, if you tab out of the form without actually selecting something, the host_id input variable is populated with the hostname and not the host_id resulting in page errors if you are not careful to select.

To Reproduce

See the notes above.

Expected behavior

Cacti should always put the ID in that form object.