fix: allow to change formatter on PMTV
It is not possible to change formatter of the position readout in PMTV.
PMTV is a TaurusValue widget whose read widget is composed
from multiple sub-widgets. The position readout is shown
on one of these sub-widgets - the lbl_read
label.
Override setFormat
of the PMTV read widget class in oder to pass the new
formatter to the lbl_read
.
Fix #1778 (closed).