Remove conditional import of managed configs for Vartheme BS5 blocks after varbase_default_content installation

Problem/Motivation

#3526576: Remove all components as they were moved to Vartheme BS5 starterkit theme
#3526581: Have all Varbase Components in the Vartheme BS5 starterkit theme

Proposed resolution

• Remove managed configs for Vartheme BS5
• Remove conditional import of managed configs for Vartheme BS5 blocks
• Move managed configs to the optional configs in Vartheme BS5

This cleanup simplifies the installation logic by decoupling block config imports from the presence of default content. The responsibility of placing or importing theme-specific blocks should not depend on whether demo content is installed. This change improves flexibility and aligns with Varbase's modular design principles.

Remaining tasks

• ✅ File an issue about this project
• ✅ Addition/Change/Update/Fix to this project
• ✅ Testing to ensure no regression
• ➖ Automated unit/functional testing coverage
• ➖ Developer Documentation support on feature change/addition
• ➖ User Guide Documentation support on feature change/addition
• ➖ UX/UI designer responsibilities
• ➖ Accessibility and Readability
• ✅ Code review from 1 Varbase core team member
• ✅ Full testing and approval
• ✅ Credit contributors
• ✅ Review with the product owner
• ✅ Update Release Notes and Update Helper on new feature change/addition
• ✅ Release varbase-10.1.0-alpha2, varbase_core-10.1.53

Varbase update type

• ✅ No Update
• ➖ Optional Update
• ➖ Forced Update
• ➖ Forced Update if Unchanged

User interface changes

• N/A

API changes

• N/A

Data model changes

• N/A

Release notes snippet

• Issue #3538586: Removed conditional import of managed configs for Vartheme BS5 blocks after varbase_default_content installation