Annotate the `research` and `test` files for which no further changes
are needed to successfully compile them, to not interfere with periodic
tasks such as spec reference bumps.
* "official" -> "scenarios", like the submodule
* fewer test binaries - various compile hacks have been improved over
time, test suite should follow
* remove obsolete bls tests - there are better test vectors in
nim-blscurve
* remove obsolete mentions of `ssz_testing`
* remove obsolete comments about proc vs globals, unittest2 already uses
proc's
Etan Kissling
tersec
Jacek Sieka