in the dashboard the validation on autocomplete can be disabled
therefore it is no longer necessary to check for the validity
of the github url in the way it was previously implemented

the validation of the github url when a component is added has
been improved

check whether the value in ui select has changed, since otherwise
the selection must not be stored in the users internal storage

use a function that checks whether the value in a select form has
changed and must be saved

that way some common errors can be handled in a better way: such
as when no file was picked or when the file could not be parsed