[BUG]: Images flickable has performance bug when all nodes selected.

[mohsenkondori]

Describe the bug When all nodes were selected, in nodes rect, the image flickable position updated very slowly.

Check it: #174

To Reproduce Steps to reproduce the behavior:

1. Select nodes (All nodes: Ctrl+A)
2. The selection process was very slow...

Expected behavior The selection process should be more smooth.

Software Versions Application version: (add either official git release version or git SHA) Firmware version: (add either official git release version or git SHA)

Additional context Add any other context about the problem here.