Optimize K-Truss (#4742)

This PR introduces several optimization to speed up K-Truss. In fact, our K-Truss implementation computes the intersection of all edges regardless they are weak or not which can be very expensive if only few edges need to be invalidated. By running `nbr_intersection` on the weak edges, this considerably improves the runtime.

Authors:
  - Joseph Nke (https://github.com/jnke2016)
  - Ralph Liu (https://github.com/nv-rliu)

Approvers:
  - Chuck Hastings (https://github.com/ChuckHastings)
  - Seunghwa Kang (https://github.com/seunghwak)

URL: #4742