simplify verification

[debris]

This pr attempts to simplify a bit a header/block verification process.

Changes:

• I removed NoopVerifier as it was never used
• after removal of NoopVerifier, the only remaining implementation of Verifier was CanonVerifier so I also removed it as well as the trait itself
• last param of fn verify_block_family is no longer optional. (it was always called with Some)
• I split fn verify_header_params into 2 functions:
  • fn verify_header_params
  • fn verify_header_time which does only timestamp verification of the header
• I formatted several extremely long lines so they are now more readable

[dvdplm]

* I split `fn verify_header_params` into 2 functions

What was the reason you did this? Like, what's the gain having them split in two?

[dvdplm]

lgtm

Did you notice any difference in the benches? I don't expect much of an impact, but you never know.

[debris]

What was the reason you did this? Like, what's the gain having them split in two?

The function was taking an additional argument - bool, which was used to decide whether time of the header should be checked. By splitting it into two functions I reduced the complexity of the code.

Did you notice any difference in the benches? I don't expect much of an impact, but you never know.

No, I forgot to alter the verify_block_family function call in one of the tests. It's fixed in d90e057