Vector Dot product addition to block sgs

[mndevec]

There are couple of todos in src/sparse/impl/KokkosSparse_gauss_seidel_impl.hpp file related to vector dot product.

Around lines - 332, 343 and 456 there are 3 parallel reduces that does dot product using vector lanes.
These should be replaced with vector dot products when implemented.

[srajama1]

@vqd8a Did you implement a vector dot product ?

[vqd8a]

@srajama1 Not yet. I just implemented the team-based dot product.