Mer: Align "Virtual machine" QFormLayout contents left

Signed-off-by: Jarkko Lehtoranta <jarkko.lehtoranta@jolla.com>
Mer: Fix emulator QFormLayout fields on OSX

- Allow expanding fields to grow
- Change horizontal size policy for config folder, ssh folder and ssh key

Signed-off-by: Jarkko Lehtoranta <jarkko.lehtoranta@jolla.com>
Mer: Fix hardware device QFormLayout fields on OSX

- Allow expanding fields to grow
- Change privateKeyLabelEdit horizontal size policy to expanding

Signed-off-by: Jarkko Lehtoranta <jarkko.lehtoranta@jolla.com>