Sets markdown files to be opened as Jupyter Notebooks in JLab.

See https://direnv.net. Currently adds bin-dir to PATH and activates
virtual environment if it exists.

[ci] Fix sanitizer job

See merge request ogs/ogs!4503

[ci] Fix sanitizer and wheel jobs

See merge request ogs/ogs!4501

[cmake] Use header-only fmt lib. Should fix wheels.

See merge request ogs/ogs!4500

[web] Update text for Video Tutorial

See merge request ogs/ogs!4496

Fixed one LARGE parallel computing test

Closes #3374

See merge request ogs/ogs!4499

[ci] Introduce MR label ci_large for enabling large tests.

See merge request ogs/ogs!4491

Fix point heat source notebook typesetting

See merge request ogs/ogs!4461

New image provided by Kata Kurgyis.

[cmake] CMAKE_GENERATOR should be taken into account for ext cache dir.

See merge request ogs/ogs!4497

[cmake] Cache external dependencies in CPM_SOURCE_CACHE.

See merge request ogs/ogs!4494

[nb] Use vtk-osmesa wheel

See merge request ogs/ogs!4493

[web] New docs for tools

See merge request ogs/ogs!4487

 - MeshMapping,
 - MoveMesh,
 - createLayeredMeshFromRasters,
 - ExtractMaterials,
 - checkMesh,
 - generateGeometry,
 - MoveGeometry,
 - OGS2VTK, and
 - editMaterialID

[tools] New function to print material IDs

See merge request ogs/ogs!4492

Adding new function for material ids output to MeshInformation.
Using it in tooling before and after mesh modifications.

If CPM_SOURCE_CACHE is set and outside the build directory.

Full build is cached in $CPM_SOURCE_CACHE/_ext/[NAME]/[HASH]

Hash is based on all parameters given to build the dependency (version
info, cmake options).