Refactor navbar

[Jad31]

What kind of change does this PR introduce?

Refactor the navbar to match the new figma design. Fix responsive issues as well

Issue Number:

• Closes # <!-- Replace with the issue number this PR resolves -->
• Related to #558
• Others?

Screenshots/videos:

Before	After

If relevant, did you update the documentation?

Summary

Does this PR introduce a breaking change?

[frouioui]

Linked to https://github.com/vitessio/arewefastyet/issues/525