Bad z-index for blocks error dialog

[ewpatton]

Describe the bug

The error dialog in the blocks editor has a lower Z-index than the Blockly scrollbars, leading to visual glitches when errors occur:

Affects

• Designer
• Blocks editor
• Projects Explorer
• Companion
• Compiled apps
• Buildserver
• Debugging
• Other... (please describe)

Expected behavior

The error dialog should appear above the scrollbars.

Steps to reproduce

1. Make the window fairly narrow horizontally
2. Trigger the bug in Cannot remove pie chart entries on Android #3262

[YashSachdeva]

Updating the z-index of the error dialog will resolve this.
Also, verify that the scrollbars z-index is lower to avoid further conflicts.

[Flying-Pegasus]

@YashSachdeva is this issue still open, I want to work on it

[ewpatton]

@Flying-Pegasus I believe nobody else is working on it if you want to attempt a fix.

[Flying-Pegasus]

@ewpatton okay thank you

[soniya-malviy]

@ewpatton I want work on this issue can you please assign me this issue.