Change TargetSpace of GFE::LocalEnergy to be a variadic template and Change from Virtual Function to lambda function in cosserat-continuum

@osander: Oldest two commits of !48 (merged) with the comments.

enabled an automatic merge when the pipeline for 43d3626a succeeds

added 2 commits

• bc21047d - Change from Virtual Function to lambda function in cosserat-continuum
• ec590d57 - Change TargetSpace of GFE::LocalEnergy to be a variadic template

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added 4 commits

• ec590d57...95810622 - 2 commits from branch osander:master
• 156dbcf0 - Change from Virtual Function to lambda function in cosserat-continuum
• 22e8057e - Change TargetSpace of GFE::LocalEnergy to be a variadic template

Compare with previous version

@osander this can be merged now, right? I thought you had already set this to be merged automatically?

merged

mentioned in commit 77844fbb