Feature/cleanup ctors dofvec pgb
This MR does the following:
- Replace explicit type
DefaultGlobalBasis
in constructor argument ofDOFVector
andParallelGlobalBasis
with a concept check forDune::Functions::GlobalBasis
for the conversion of adune-functions
-style basis into aParallelGlobalBasis
. - Shorten interface methods of
ParallelGlobalBasis
(Cleanup)