De-duplicate Gen Basis Matrices

[jeremylt]

Follow-up on #1735

We've got the code for preventing duplication of the restriction operations. This same code can be modified to make sure we don't LoadMatrix the same matrix multiple times. This duplication isn't a big deal with tensor bases, but its important for non-tensor bases. Currently, we have 2x duplication of those mats for the BPs - once for the input field and once for the output field with the exact same basis.