FOCA-137: Fix adjusting of state labels

Prior to this patch, a change of the state label could cause the visual
representation of this element to loose its initial geometry. This patch
now no longer recalculates the geometry of a state layout item when the
label got changed. Leave that to the layouter if needed.

Initially, that code was there to be able to get a somewhat useful
visual appearance of the state chart when no layouter was present.

Change-Id: Idf3d2bdb961b021220905d69285fdbddcd17b337
Implement Keyboard navigation for the state machine view

Change-Id: I2a3ae8a7aed6c03dc1229b558e97b039fd2d4d1c
Reviewed-on: https://codereview.kdab.com/12479
Reviewed-by: Continuous Integration <build@kdab.com>
Reviewed-by: Kevin Funk <kevin.funk@kdab.com>
Pimpl SME::View

Change-Id: I1cbd3bff3c8c4819a2d7453fc5f0ae2fb154a47b