Keeping track of where reg tests need to be changed to hypre

[mbkuhn]

As changes are made to address #1289, the number of diffs in this PR will go down, eventually to 0.

This branch was initiated as a broad stroke to catch all instances of tpetra in reg_tests. However, some tests may not need to be converted if they specifically are meant to target trilinos solvers, and there is adequate coverage from the other hypre tests.