Remove a bunch of uninteresting samples

These are mostly duplicative of GMs and don't offer any interesting
interactive features.

Bug: skia:13870
Change-Id: I3ceeaf744cc43ceda1465ed599979a37ae7cae86
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/597563
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
18 files changed