TES process

* less privacy
* multiple process variables

Remove iostream include

Only istream is required here.

small fixes

Splitting FileIO part 4

Splitting FileIO part 3

Remove unused stuff MathLib/LinAlg

remove #ifdef OGS_USE_EIGEN from local matrix related files

Extend local asm interface

[FileIO] GmshInterface 

clang-tidy '-checks=modernize-use-auto,readability-simplify-boolean-expr' -p=../b/ FileIO/GMSHInterface.cpp

Control switches rotate and keep_preprocessed_geometry.

Avoid implicit generation of
- copy constructor,
- move constructor,
- assignment operator and
- move assignment operator.

The check prevents to insert a line that is already a part of the node polygon.