crypto/internal/fips: move most tests to crypto/internal/fipstest

crypto/internal/fips: move most tests to crypto/internal/fipstest

As explained in fips_test.go, we generally want to minimize tests inside
the FIPS module. When there is a relevant calling package, the tests
should go there, otherwise in fipstest.

This required redoing a bit the CAST failure tests, but the new version
is actually more robust because it will fail if a _ import is missing.

Since TestCAST doesn't print a line for each passed CAST anymore, made
GODEBUG=fips140=debug do that, in case we need to show it to the lab.

For #69536

Change-Id: I0c1b82a4e9ee39e8df9bbe95bebb0527753f51c8
Reviewed-on: https://go-review.googlesource.com/c/go/+/627955
Reviewed-by: Daniel McCarney <daniel@binaryparadox.net>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Auto-Submit: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>