fix: remove VRFProve

[ulbqb]

Description

VRFProve() function was incorrect implementation and unnecessary. So, I removed VRFProve() function.

Motivation and context

How has this been tested?

Screenshots (if appropriate):

Checklist:

• I followed the contributing guidelines and code of conduct.
• I have added a relevant changelog to CHANGELOG.md
• I have added tests to cover my changes.
• I have updated the documentation accordingly.
• I have updated API documentation client/docs/swagger-ui/swagger.yaml

[codecov]

Codecov Report

Merging #731 (303cea5) into main (5ed82db) will decrease coverage by 0.01%.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #731      +/-   ##
==========================================
- Coverage   61.96%   61.95%   -0.02%     
==========================================
  Files         877      877              
  Lines       98764    98762       -2     
==========================================
- Hits        61200    61185      -15     
- Misses      33955    33960       +5     
- Partials     3609     3617       +8     

Impacted Files	Coverage Δ
crypto/ledger/ledger_secp256k1.go	52.89% <ø> (+0.75%)	⬆️
x/token/validation.go	72.72% <0.00%> (-18.19%)	⬇️
x/collection/msgs.go	41.29% <0.00%> (-1.67%)	⬇️
x/token/msgs.go	34.51% <0.00%> (+2.03%)	⬆️