fix #466: add UI scaling feature

[NancyWei123]

PR Description

add UI scaling feature so that we can use mouse to room in and room out and drag the screen.
Here is screenshot.

issue: However, I encounter a problem when running both the original branch and the add-feature-UI-scaling branch. I believe it is caused by a missing file.

Related Issues

• Closes Please add UI scaling #466

Checklist

• [✓] I have gone through the contributing guide
• [✓] I have updated my branch and synced it with project main branch before making this PR
• [✓] I am using the latest Flutter stable branch (run flutter upgrade and verify)
• I have run the tests (flutter test) and all tests are passing
  I haven't passed all the tests and I don't know the reason.

I’m new to open source, so my code might need some improvements — I appreciate any feedback! Thank you so much! ## Added/updated tests? _We encourage you to add relevant test cases._

• Yes
• [✓] No, and this is why: don't need a test

OS on which you have developed and tested the feature?

• [✓] Windows
• macOS
• Linux