Entity Panel: Show entity IDs when dev mode on

[Innders]

Story

A developer wants to quickly see the ID of an entity.

Solution

When in Dev mode show a copy button for the entity ID inside DetailsPanelHeader.jsx.

• Only shows when in dev mode
• Hover effect
• Text selectable
• Click to copy to clipboard (helper function somewhere)
• Overflow hidden (does not wrap)

[martastain]

quickly see and preferably copy :)