fix: createCredentialIssueRecordRequest schemaId field to be Option[String]

[yshyn-iohk]

Description:

This refactoring is required because the schemaId property should never accept the value of a string array for currently supported VC types. The corresponding objects should be used to create VCDM 1.1 and VCDM 2.0 VCs.

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

[github-actions]

Integration Test Results

20 files  ±0  20 suites  ±0   2s ⏱️ ±0s
55 tests ±0  55 ✅ ±0  0 💤 ±0  0 ❌ ±0 
97 runs  ±0  97 ✅ ±0  0 💤 ±0  0 ❌ ±0 

Results for commit dc98dcf. ± Comparison against base commit 2fb833a.

♻️ This comment has been updated with latest results.

[github-actions]

Unit Test Results

104 files  ±0  104 suites  ±0   20m 55s ⏱️ -2s
882 tests ±0  874 ✅ ±0  8 💤 ±0  0 ❌ ±0 
889 runs  ±0  881 ✅ ±0  8 💤 ±0  0 ❌ ±0 

Results for commit dc98dcf. ± Comparison against base commit 2fb833a.

♻️ This comment has been updated with latest results.

[coveralls]

coverage: 48.743% (-0.05%) from 48.797%
when pulling dc98dcf on feat/vcdm-1_1-oas-refactoring
into 2fb833a on main.