[create-sitecore-jss] Bug fix: Removes requirement for base initializer when adding appName to appNames array in case we are scaffolding a non base app

[yavorsk]

• [x] This PR follows the Contribution Guide
• [x] Changelog updated
• [ ] Upgrade guide entry added

Description / Motivation

Removes requirement for base initializer when adding appName to appNames array in case we are scaffolding a non base app; fixes 'Should create nextjs app with Styleguide using post-initializer template only' development test

Testing Details

• [x] Unit Test Added
• [ ] Manual Test/Other (Please elaborate)

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)