Replace std::valarray with Eigen::VectorXd

Replace std::valarray with Eigen::VectorXd

For consistency mainly, but also save one instantiation of the shape functions. Also the valarray is kind of obsolete and Eigen provides equivalent substitute.

1. [-] Feature description was added to the changelog
2. Tests covering your feature were added? Existing tests
3. Any new feature or behaviour change was documented?

changed milestone to %6.5.4

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added 14 commits

• a34663a2...8500da52 - 13 commits from branch ogs:master
• e34cbe28 - Replace std::valarray with Eigen::VectorXd

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approved this merge request

mentioned in commit 2c94b1cc

merged