Improve platform responsiveness

[abhi1203]

Describe the bug
For some desktop screen sizes, the platform doesn't respond too well.

And some times header sections look like this:

[mdshamoon]

@abhi1203 please suggest the changes that we can make here. A design file would be a great help

[abhi1203]

For this @mdshamoon based on our conversation, we're planning to force the sidebar to collapse for screens between 768 to 1280px. But, on hovering over the sidebar, the sidebar will open as an overlay and then again hide after the use has clicked on the the option.
here: https://www.figma.com/file/SEWpT6NLTjwH2W6PrRdFvq/Glific%2FApp?node-id=42%3A44441&t=y6FVYmdZZZJPFT4g-4