Mouse scroll to Zoom in/out in map view

[rohit645]

This pull request makes the following changes:

• UI enhancement (Mouse wheel to Zoom in/out in the map view.)

Testing checklist:

• I certify that I ran my checklist

[ushbot]

Hey @rohit645,
thank you for your Pull Request.

@rjmackay It looks like this brave person signed our Contributor License Agreement. 👍

Always at your service,

clabot

[Angamanga]

@rowasc @tuxpiper Can you review while I am off? Thank you 🙏🏻

[tuxpiper]

I think people will like this 👍 Thanks!

[rohit645]

Thanks a lot @tuxpiper.