Update for AssemblerLib::MeshComponentMap.
Prepare SerialVectorMatrixBuilder for AssemblerLib.
SerialVectorMatrixBuilder: Remove default VectorType_ template arg.
Split SerialVectorMatrixBuilder into Dense and Lis variants.
Move SerialVectorMatrixBuilder into AssemblerLib.
Correct global assembler operator() constness.
Extract AssemblerLib::SerialExecutor from vector/matrix builder.

Both are independent of each other.
Remove element type from serialExecute. Add iterator version.
Invert argument order in serialExecute().
Make SerialVectorMatrixBuilder create functions static.
Add SerialVectorMatrixBuilder test.

It is checking only creation and sizes of the vector and matrix.
Add SerialExecutor test for std::vector.
Remove unused vector and matrix assemblers.
Move LinearSystemAssembler and its test to AssemblerLib.

Cleaning up the files and corresponding directories as well as cmake inputs.