shadow fake xmss

[turuslan]

• --shadow flag to use fake xmss provider in shadow.
  • treats all signatures as valid.
  • doesn't read/write keys (many megabytes) for each node.
• publish/receive block/attestation logs, for python parsing and plots
  • soralog truncates long messages, writing to stdout conflicts with soralog
    • maybe don't print all block attestations
    • or write to custom file
• update gen_shadow_yaml.sh script