demo_scrollview: buggy mouse selection

[tmssngr]

V version: V 0.4.10 d54a823 UI version: latest OS: Windows 11

What did you do?

• click-and-hold left mouse button inside right view
• move over to left view
• release mouse button over left view
• move mouse back over right view -> selection continues until clicked again

What did you expect to see? Releasing the mouse button, no matter where, should stop the selection. When the mouse button is pressed, you need to enable to get all mouse events to this control until it is release.

What did you see instead? see above

[tmssngr]

On Windows this would require SetCapture on LMB down and ReleaseCapture on LMB up.