Implement consensus de/serialization in Clarity

[kantai]

Description

This PR adds to-consensus-buff and from-consensus-buff methods to the Clarity2 native methods.

Applicable issues

• Implements Feature request: allow hashing functions to hash other Clarity types #2693 by allowing arbitrary Clarity types to be transformed into buffers
• Implements the buffer serialization aspects of the SIP-018 Signed Structured Data stacksgov/sips#57 proposal

Additional info (benefits, drawbacks, caveats)

These methods are both fallible -- this may be surprising in the case of to-consensus-buff, but the reason is that some legal Clarity values serialize into buffers that are larger than the maximum Clarity value size; this is because of the type prefix and length encoding.

The typing of to-consensus-buff produces a buffer size which is the maximum possible buffer size for its input. In the case of uints, ints, and bools this is always correct. For other types, however, it will be an overestimate in many cases (e.g., for principal, it assumes the principal is a contract with the longest possible Clarity name).

[codecov]

Codecov Report

Merging #3132 (d8f7628) into next (e7f3c55) will decrease coverage by 0.01%.
The diff coverage is 97.43%.

@@            Coverage Diff             @@
##             next    #3132      +/-   ##
==========================================
- Coverage   83.64%   83.63%   -0.02%     
==========================================
  Files         267      268       +1     
  Lines      209188   209655     +467     
==========================================
+ Hits       174981   175338     +357     
- Misses      34207    34317     +110     

Impacted Files	Coverage Δ
clarity/src/vm/analysis/arithmetic_checker/mod.rs	92.70% <ø> (ø)
clarity/src/vm/analysis/errors.rs	70.33% <0.00%> (-0.34%)	⬇️
clarity/src/vm/functions/conversions.rs	81.63% <92.85%> (+2.64%)	⬆️
clarity/src/vm/types/serialization.rs	94.58% <94.59%> (-0.01%)	⬇️
clarity/src/vm/analysis/type_checker/tests/mod.rs	98.92% <98.40%> (-0.03%)	⬇️
clarity/src/vm/tests/simple_apply_eval.rs	99.53% <99.41%> (-0.02%)	⬇️
clarity/src/vm/analysis/read_only_checker/mod.rs	86.57% <100.00%> (+0.12%)	⬆️
...rc/vm/analysis/type_checker/natives/conversions.rs	100.00% <100.00%> (ø)
...larity/src/vm/analysis/type_checker/natives/mod.rs	96.66% <100.00%> (+0.03%)	⬆️
clarity/src/vm/docs/mod.rs	88.29% <100.00%> (+0.04%)	⬆️
... and 33 more

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[jcnelson]

typo -- "in in a"

[kantai]

Removed in d8f7628

[jcnelson]

Overall LGTM. Just had a few superficial / edification comments, with a request for a (trivial) additional bit of test coverage. Thanks for whipping this up!

@MarvinJanssen do you want to do a pass on this before merging? Let us know.

[MarvinJanssen]

Amazing, I was working on a to-consensus-buff for the REPL but this code is a lot more elegant. Can easily it be ported to the REPL (and thus Clarinet) before 2.1 launches?

[obycode]

Can easily it be ported to the REPL (and thus Clarinet) before 2.1 launches?

Migrating the REPL to use this canonical clarity lib is high on my todo list. Once that is done, we would enable a 2.1 option for testing before 2.1 is launched.

[pavitthrap]

lgtm

[jcnelson]

Cool, looks like all my comments were addressed 👍