Rotation scan directions

On some discussion with @graeme-winter we think that the best way to represent positive/negative rotations w.r.t. the diamond lab coordinate system is to:
- keep omega angles increasing
- change the `/entry/sample/transformations/omega` `vector` attribute to match the rotation direction so that is is always right-handed as described in https://journals.iucr.org/m/issues/2020/05/00/ti5018/ti5018fig2.html

Files created in this way are being tested with hyperion to see if they work with data processing software. If yes, or no and we can fix the processing software, then we should implement checks to make sure this is how they are recorded here