Bug Fix: Made ToolBar Icons Responsive

[arjunjayan999]

This PR fixes issue #4351 and includes several changes to the lib/materialize-iso.css file, primarily focusing on adjusting the font sizes and widths of icons within navigation elements.

Font size adjustments:

• Increased the font size of .materialize-iso nav .aux i.material-icons from 32px to 48px.
• Changed the font size of .materialize-iso nav .main i.material-icons and .materialize-iso nav .aux i.material-icons from fixed pixel values to viewport width units (5.3vw).
• Updated the font size of .materialize-iso nav .main i.material-icons and .materialize-iso nav .aux i.material-icons to 7.5vw and adjusted the margin values accordingly.

Width adjustments:

• Removed the width properties from .materialize-iso nav .main i.material-icons and .materialize-iso nav .aux i.material-icons.

Before

After

Responsive.Toobar.Icons.mp4

Note

• It now accomodates till the width of 525px or so, beyond this it is better to implement a hamburger menu of sorts for navbar. That is why I have not handled the media query of 400px in PR.

[arjunjayan999]

@walterbender please review it.