The evaluation of solid density is moved to the
updateConstitutiveRelations.

The 'name' in process construction is also used after
the process construction and so it can not be moved
anyway. Taking it by const-ref avoids an extra copy
here (and silences a cppcheck warning).

Use const references where necessary.

Rename a the method from getNumberOfComponents() to getNumberOfGlobalComponents()
in class LocalToGlobalIndexMap.

The fmt library happily accepts std::string without
any conversions.

Fixes multiple copyright messages in the doxygen docu.

ag '\\file' -L --ignore=ThirdParty *Lib |xargs  sed -i 's/\(.*\)\\copyright/\1\\file\n\1\\copyright/'

Adding a new function for parameter lookup of optional tags.

This reverts commit d825ea54.

Also add default initialization where needed.

See previous commit for details.