Rotation snapping and isometric view

This update introduces rotation snapping and an isometric view button in the camera views selector.

Changes

• 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.