New Editor Opened bpmn files related issues

[madhurrya]

1. When there are multiple files opened in the editor, when one diagram is played/reset, that seems to apply to the other open diagrams. Please see this video.
   https://drive.google.com/file/d/1tcoTv8d3Smdk3NvL90OKRl-Xuzf_Kl5n/view?usp=sharing

[madhurrya]

2. When many files are opened in the editor it doesn't look nice. It might be nice if we can remove that scroll bar and may be add 2 arrows on the two sides to scroll