Consider reducing spin box increments for radians

[iche033]

Desired behavior

Currently clicking up/down arrows in GzPose's roll, pitch, yaw spin boxes increments / decrements the value by 1 rad, which is relatively large. Consider reducing it to something smaller, e.g. 0.1.

Alternatives considered

Leave as is.

Implementation suggestion

In GzPose.qml, the same writeable GzSpinBox component is used for setting x, y, z, roll, pitch, and yaw values. We may need to create a different writeable spinbox compoent for roll, pitch, yaw that has a different stepSize