[TASK] Unified Config support - Restore App properties

[igpetrov]

Related to

Epic: https://github.com/camunda/product-hub/issues/2486
Related to: camunda/camunda#39379
Properties tracking (project internal): https://docs.google.com/spreadsheets/d/1R4epsy6DWemA8_76cUE6zOGUFbrXCXlM2reXnKFuz7Y/edit?gid=818158292#gid=818158292

Overview

Hello team, requesting support of new properties:

• camunda.system.restore.validate-config to replace legacy property zeebe.restore.validateConfig
• camunda.system.restore.ignore-files-in-target to replace legacy property zeebe.restore.ignoreFilesInTarget

Required for 8.9.

[hisImminence]

@bkenez did you already evaluated this one for the unified config wave? 🙏 If not needed please close.