Fix block producer genesis block hash mismatch

[leventeliu]

• Use standard verifier.DefaultHashSignVerifierImpl in BPBlock instead of the old implementation.
• Split Sign and Verify methods of verifier interface into SetHash, SignHash, VerifyHash, and VerifySignature.
• Use SetHash to rewrite genesis block hash on cqld bootstrap, and use VerifyHash to verify it in the main chain.

[codecov]

Codecov Report

Merging #217 into beta will increase coverage by 0.13%.
The diff coverage is 93.75%.

@@            Coverage Diff             @@
##             beta     #217      +/-   ##
==========================================
+ Coverage   76.27%   76.41%   +0.13%     
==========================================
  Files         136      136              
  Lines       11230    11247      +17     
==========================================
+ Hits         8566     8594      +28     
+ Misses       2005     1999       -6     
+ Partials      659      654       -5

[xq262144]

Approve

[auxten]

LGTM