[localevaluation.ESV2007] added 2nd variant

Which takes a diffusion factor and a diffusion tensor.
[products.ESV2007] added first draft of a 2nd variant

This one takes a diffusion factor and a diffusion tensor.
[operators.fluxreconstruction] extend signature
[operators.fluxreconstruction] added first draft of a 2nd variant

Which takes a diffusion factor and a diffusion tensor.