Adds new Theme API functions

[johannesconsulting]

Description

Adds 2 new functions that are related to the new APIs introduced with 14.4

Type of change

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that makes existing functionality work differently)
• [x] Documentation update (psPAS website or command help content)
• [ ] Other (see description)

How Has This Been Tested?

• [x] Pester test(s) update required
• [ ] Pester test(s) updated
• [ ] Pester test(s) passing

Test Configuration:

• PowerShell version: 7
• CyberArk PAS version: 14.4
• OS Version: Windows Server 2022

Checklist:

• [x] My code follows the style guidelines of this project
• [x] I have followed the contributing guidelines.
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] I have made corresponding changes to the documentation
• [x] My changes generate no new test failures or errors
• [ ] I have added tests that prove my fix is effective or that my feature works
• [ ] New and existing unit tests pass locally with my changes
• [ ] I have opened & linked a related issue
• [ ] I have linked a related issue