Revert "[assembler.wrapper] adds syncing in matrix constraints"

This reverts commit 0c71028be4dc41294c8fdf840913a67fa549bd5a.
I was still having issues with this despite the locking.
So I switched back to not assembling constraints in parallel.
[assembler.system] fixes a a name shadowing warning
[elliptic-sipdg-discretization] readd current_grid_width()
- without it, compiler complains about pure virtual function
[elliptic-sipdg-discretization] readd current_grid_width()
- without it, compiler complains about pure virtual function
[spaces.interface] add template parameters to SpaceInterface, refs #14
[spaces.tools] add template parameters for SpaceInterface, refs #14
[assembler.local.codim*] add template parameters for SpaceInterface, refs #14
[assembler.system] add template parameters for SpaceInterface, refs #14
[assembler.wrapper] add template parameters for SpaceInterface, refs #14
[discretefunction] add template parameters for SpaceInterface, refs #14
[functionals] add template parameters for SpaceInterface, refs #14
[operators.elliptic-*] add template parameters for SpaceInterface, refs #14
[operators] adapt apply method to SpaceInterface changes, refs #14
[playground.mapper] add template parameters for SpaceInterface, refs #14
[products] add template parameters for SpaceInterface, refs #14
[spaces.cg.base] add template parameters for SpaceInterface, refs #14
[playground.spaces] add template parameters for SpaceInterface, refs #14
[functionals.swipdg] remove unnecessary typenames, refs #14
[test.spaces] add template parameters, refs #14
[spaces.cg.fem] remove definitions of dims from Traits, refs #14