[all] many type fixes

.gitignore

ogstools/meshlib/boundary.py

ogstools/meshlib/boundary_set.py

ogstools/meshlib/boundary_subset.py

ogstools/meshlib/gmsh_meshing.py

ogstools/meshlib/mesh_series.py

ogstools/meshlib/region/region.py

ogstools/meshlib/xdmf_reader.py

ogstools/meshplotlib/animation.py

ogstools/meshplotlib/core.py

ogstools/meshplotlib/plot_features.py

ogstools/meshplotlib/plot_setup.py

ogstools/meshplotlib/utils.py

ogstools/msh2vtu/__init__.py

ogstools/propertylib/property.py

ogstools/studies/convergence/convergence.py

...ls/studies/convergence/examples/steady_state_diffusion.py