[cleanup][io] Small fixes in raster image reader

See merge request !3365

[io][gnuplot] Fix variable type

See merge request !3364

[test][components] Use constexpr and is_detected

Closes #1208

See merge request !3360

[installexternal] Do some safety checks on tar archives using TarSafe

Closes #1207

See merge request !3361

[fmt] Update shipped version to 9.1.0

See merge request !3362

In C++20 mode passing non-constexpr format string yields a compiler
error. In that case, we have to use vformat(varstr, std::make_format_args(a, b, c...))

[bin][postprocessing] add pvpython version check for 5.11

See merge request !3355

remove ".git" with endswidth check rather than rstrip

See merge request !3359

[cleanup] [test][md][stokesdarcy][1p2c] remove unused properties_stokes.hh

See merge request !3356

[test][stokes] Add stabilized Box-Box donea test

See merge request !3350

[rans] Allow for more general solution types in addDynamciwWallProps

See merge request !3351

In coupled models we might pass some proxy solution generated by partial.
This is tested in the dumux-course example.

Feature/cvfe improvements

See merge request !3349