Crypto v0.43 Audit updates

[technicallyty]

Description

• Bytes ranamed to TestBytes in test files so the functions get tested
• Add TestBytes to secp256r1 pubkey test file
• Add nil check to secp256r1 bytes methods as without it they throw nil dereference errors on nil keys
• Update comment in esdca/pubkey Address() function to explicitly state its functionality/side effect (creates an address if nil)

ref: #9218

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Before we can merge this PR, please make sure that all the following items have been
checked off. If any of the checklist items are not applicable, please leave them but
write a little note why.

• Targeted PR against correct branch (see CONTRIBUTING.md)
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• Code follows the module structure standards.
• Wrote unit and integration tests
• Updated relevant documentation (docs/) or specification (x/<module>/spec/)
• Added relevant godoc comments.
• Added a relevant changelog entry to the Unreleased section in CHANGELOG.md
• Re-reviewed Files changed in the Github PR explorer
• Review Codecov Report in the comment section below once CI passes

[codecov]

Codecov Report

Merging #9292 (ad9e60e) into master (709ab08) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #9292   +/-   ##
=======================================
  Coverage   60.32%   60.33%           
=======================================
  Files         591      591           
  Lines       36936    36940    +4     
=======================================
+ Hits        22282    22288    +6     
+ Misses      12683    12682    -1     
+ Partials     1971     1970    -1     

Impacted Files	Coverage Δ
crypto/keys/internal/ecdsa/pubkey.go	69.56% <ø> (ø)
crypto/keys/secp256r1/privkey.go	82.35% <100.00%> (+2.35%)	⬆️
crypto/keys/secp256r1/pubkey.go	80.00% <100.00%> (+3.07%)	⬆️
crypto/keys/internal/ecdsa/privkey.go	82.60% <0.00%> (+8.69%)	⬆️