[!338] Use a different template parameter for the linearization point

Merge branch 'feature/linearizationpoint-template-parameter' into 'master'

ref:extensions/dune-codegen Last backport from diss branch.

See merge request [extensions/dune-codegen!338]

  [extensions/dune-codegen!338]: gitlab.dune-project.org/extensions/dune-codegen/merge_requests/338