* "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
So far, SSZ tests for `uint128` and `uint256` integers were disabled
due to "compile-time issues". The code has been adjusted to support
those additional test vectors, and the corresponding tests have been
enabled.
* add random tests and rename "Official" to "Ethereum Foundation"
* checkDir = true covers dirExists(...)
* invalidate CI EF fixtures cache
* more correct cache invalidation