Rudimentary support of rendering of vector data (e.g. velocity) on mesh map layers.
Rendering can be adjusted by QgsMeshRenderer*Settings. Only in Python
API, no GUI widgets for styling present.
Introducting MDAL, QgsMeshLayer, mesh data providers (mesh_memory, mdal)
to read and visualize raw meshes: vertices and faces. Support dragging
2dm files from browser on canvas to visualize 2dm meshes.
Support for QgsMeshLayer in Python API.