feat(ui): postgres ha cluster - "extensions" (#548) and "filesystem" (#549)

Description

• Refactored playbook commands for cluster, now they are reusable
• Added Filesystem both inside the form and in the snippets
• Added Extensions both inside the form and in the snippets

Related issue

#548 #549

Examples

Checklist

• MR description has been reviewed
• MR changes are functionally tested
• MR does NOT have API/CLI changes OR there are API/CLI changes and they have been reviewed & DOCS ARE ADJUSTED (reference doc, etc)
• MR does NOT have UI changes OR there are UI changes and they have been reviewed & UX IS REVIEWED

Closes #548