fix: update blsCreateProof expected response to promise

[chiechelski]

Description

• Tests for the changes have been added (for bug fixes / features)
• The commit message(s) follow conventional commits
• Documentation has been added / updated (for bug fixes / features)
• Changes follow the contributing document.

Motivation and Context

When using rn-bbs-signature library this method will not work because it returns a promise.

Does this PR introduce a breaking change?

• Yes
• No

Which merge strategy will you use?

• Squash
• Rebase (REVIEW COMMITS)

[github-actions]

Total Coverage: 88.64%

Coverage Report

File	Branches	Funcs	Lines	Uncovered Lines
src
BbsBlsSignature2020.ts	58.49%	100%	87.63%	102, 111, 119, 124, 129, 133, 207, 208, 219, 220, 318, 319, 322, 323, 341, 342, 346, 347, 361, 362, 385, 47, 48, 51, 62, 67, 71, 74, 78, 79, 80, 80, 80, 81
BbsBlsSignatureProof2020.ts	62.96%	81.25%	85.98%	173, 174, 183, 300, 301, 306, 342, 344, 348, 354, 385, 390, 402, 403, 405, 406, 424, 425, 429, 430, 44, 69, 72, 87, 96
deriveProof.ts	83.33%	100%	90.91%	123, 124, 33, 34, 83
index.ts	100%	100%	100%
utilities.ts	75%	100%	96.88%	122, 43, 82, 83