AstroBWT 20-50% speedup

Skips hashes with large stage 2 size. Added configurable `astrobwt-max-size` parameter, default value is 550, min 400, max 1200, optimal value ranges from 500 to 600 depending on CPU.

- Intel CPUs get 20-25% speedup
- 1st- and 2nd-gen Ryzens get 30% speedup
- 3rd-gen Ryzens get up to 50% speedup

src/core/config/Config_default.h

@@ -63,6 +63,7 @@ R"===(
         "max-threads-hint": 100,
         "asm": true,
         "argon2-impl": null,
+        "astrobwt-max-size": 550,
         "cn/0": false,
         "cn-lite/0": false
     },