Fix the style of the input field for chips

[nekonenene]

Proposed changes

After the change of Dogfalo#6313, the weird underline appears on the input field. This PR fixes the problem while preserving the behavior of the browser-default class.

Screenshots (if appropriate) or codepen:

Original ( https://materializecss.com/chips.html )

Current

After this change

Types of changes

• Bug fix (non-breaking change which fixes an issue).
• New feature (non-breaking change which adds functionality).
• Breaking change (fix or feature that would cause existing functionality to change).

Checklist:

• I have read the CONTRIBUTING document.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

[Smankusors]

Though the margin of the input field differs from the original, I feel it is cool.

we could also do margin: 0 !important. But in the official guide also have similiar margin. So perhaps it's fine... or maybe just delete the margin rule in .chips .input? 😅

What do you guys think about this? @materializecss/members

[Pierstoval]

I'd rather find a way to not use !important when possible indeed :p

[nekonenene]

@Pierstoval I think so, I'll try later. But it might be difficult without any breaking change...

[nekonenene]

@Pierstoval @Smankusors
Although the CSS selector is dirty, I managed to fix without !important and update the description of this PR.