Move ID29MeshPlot to ewoksmx

The following task and workflow should (I think) be moved to ewoksid29:

https://gitlab.esrf.fr/workflow/workflowhub/mxworkflows/-/blob/main/workflows/ID29MeshPlot.json?ref_type=heads

https://gitlab.esrf.fr/workflow/ewoksapps/ewoksmx/-/blob/main/src/ewoksmx/tasks/ID29MeshPlot.py?ref_type=heads

They should also be refactored to be action-oriented.

I assign this task to me as I need to understand better ewoks workflows in general and ewoksid29 in particular...

Ping @denolf @broche