Resize handles hidden behind elements

[nikku]

Describe the Bug

On our develop branch the resize handles are hidden behind elements as well as the context pad, making it hard to impossible to resize in many common usage scenarios:

develop

Released (v8.8.x, demo)

Steps to Reproduce

1. Run npm start on develop branch
2. Try resizing sub-process center left or center right
3. Observe behavior shown above

Expected Behavior

• Resize handles are shown always on top (take pointer precedence over context pad and flow handles)

Environment

• Browser: Chrome
• OS: Any
• Library version: bpmn-js@develop

[marstamm]

Root Cause: the layer-resizers is rendered behind the Process layer:

Introduced with #1481

[nikku]

Thanks for investigating.

So we shall make sure our plane layers always sit before always on top layers.