Rotation snapping and isometric view

Added rotation snapping of 5 deg while holding SHIFT.

Added Isometric view button on camera views selector.

Improvement of Dark Contrast theme.

Enable extrusion in triangle shape.

Recover default light state on file opening.

Added/improved actions to duplicate/copy/paste on general menu.

Fix issue with keyboard mapping (AZERTY / QUERTY).

Fix gizmo issue on selection.

Fix issue that prevented typing more than 180 deg on Rotation.

Fix animation interpolation issues.

Fix actions Center in object and Orientate to object.

Fix shortcuts on action to center camera into object.