Move spectests into a separate package (#8798)

* move general/phase0/bls tests

* phase0/operations tests

* phase0/sanity/blocks

* fix import

* phase0/sanity/slots

* phase0/sanity/slots minimal

* phase0/epoch_processing tests

* phase0/rewards tests

* simplify

* more simplification

* phase0/shuffling tests

* phase0/ssz_static tests

* spectest/utils

* fix build

* readme

* update test sizes

* update readme

Author: farazdagi

beacon-chain/core/blocks/BUILD.bazel

@@ -21,6 +21,7 @@ go_library(
         "//beacon-chain:__subpackages__",
         "//fuzz:__pkg__",
         "//shared/testutil:__pkg__",
+        "//spectest:__subpackages__",
         "//validator/accounts:__pkg__",
     ],
     deps = [