Follow-up of !3676 "Dropped the rotation of the shape function gradients".

Enabled using MFront in HydroMechanics

Closes #3162

See merge request !3704

[MFront] Added an if-condition to check whether the temperature is set for variable arrays in MFront::integrateStress

Changed the type of temperature reference to Parameter in the SmallDefomation project files

Closes #3168

See merge request ogs/ogs!3702

Material lib adsorbtion code improvements

See merge request ogs/ogs!3700

MeshLib MeshQuality code improvements.

See merge request !3701

Moving code from the constructor.

Small improvements

See merge request ogs/ogs!3699

Small cleanup in NumLib

See merge request ogs/ogs!3697

[CL] Use MPL to input amounts of ion exchanging species

This MR enables using the MPL to input the amounts (or molalities) of ion exchanging species as opposed to defining these quantities inside the `<chemical_system>` tag, which is what is currently possible.

This MR partially resolves issue #3164 (after this, more MRs will be added to fully resolve the issue).

1. [x] Feature description was added to the [changelog](https://gitlab.opengeosys.org/ogs/ogs/-/wikis/Release-notes-6.4.1)
2. [x] Tests covering your feature were added?
3. [ ] Any new feature or behavior change was documented?

See merge request ogs/ogs!3695