Fix selected flag overlaps other components

[VoronFX]

Description

Instead of using z-index that may interfere with other components we can achieve same effect by placing selected flag node after input node.

Screenshots (if appropriate):

Types of changes

• 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)

Checklist:

• I have used ESLint & Prettier to follow the code style of this project.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.