fix: scalar bytes for js secp256k1

[amagyar-iohk]

Description:

Found a bug in sdk-ts that randomly we would get 31 bytes instead 32 for secp256k1

KeyInitializationError: 181: Invalid byte size: 32 exptected, 31 given
      at new _Secp256k1PrivateKey (sdk-ts/packages/lib/sdk/src/apollo/utils/Secp256k1PrivateKey.ts:44:17)
      at _Secp256k1PrivateKey.derive (sdk-ts/packages/lib/sdk/src/apollo/utils/Secp256k1PrivateKey.ts:72:11)
      at _class7.createPrivateKey (sdk-ts/packages/lib/sdk/src/apollo/Apollo.ts:370:15)
      at CreatePrismDID.run (sdk-ts/packages/lib/sdk/src/edge-agent/didFunctions/CreatePrismDID.ts:35:33)
      at async Proxy.run (sdk-ts/packages/lib/sdk/src/utils/tasks.ts:65:35)
      at async sdk-ts/integration-tests/e2e-tests/src/workflow/EdgeAgentWorkflow.ts:236:11

This fix normalizes the bytes with 0 left padding

Checklist:

• My PR follows the contribution guidelines of this project
• My PR is free of third-party dependencies that don't comply with the Allowlist
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• I have checked the PR title to follow the conventional commit specification

[FabioPinheiro]

LGTM but lets also ask @goncalo-frade-iohk

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud