Front Panel elements library

Signed-off-by: Artem Godin <artem.godin@vaadin.com>
Removed legacy stuff

Signed-off-by: Artem Godin <artem.godin@vaadin.com>
Front panels:
+ PSU
+ Master
+ Stereo Input
+ VCF
+ LoFi Delay

Signed-off-by: Artem Godin <artem.godin@vaadin.com>