Remove t=0/dt=1 settings for initial residuum

See merge request ogs/ogs!4453

[utils] Raster conversion tool

See merge request ogs/ogs!4452

[ci] Win fixes

See merge request ogs/ogs!4456

[MPL] Adding IAPWS model of thermal conductivity of water to MPL

See merge request ogs/ogs!4445

Slightly relax CTests tolerances

Closes #3355

See merge request ogs/ogs!4448

Updated comments

Added entry to docs

This code has not been tested yet.
The code in this commit is refactored / modified version of
implementation of IAPWS viscosity written by Haibing Shao.

Generate mesh output from GML input

See merge request ogs/ogs!4431