feat: Add slot to override navbar logo

[mikeeus]

Adds a prop called logo of type NavbarLogo that lets the user override the default logo.
Addresses #238

[marinhoarthur]

@mihailmarcu please review.

[mihailmarcu]

Hey @marinhoarthur, @mikeeus,
The best way to implement such functionality is definitely not props. I think the best solution here is #slots. This will allow us to change not only the logo but also the structure, this solution using props does not allow you to use the svg code directly and manipulate with colors etc.

Also, some developers will want to have different dark theme images or use the figure tag.

[mikeeus]

@mihailmarcu That's a great idea! I've updated the PR to replace the <router-link> with a named slot called logo.
Is that what you had in mind?

[mihailmarcu]

Hey @mikeeus,
Thanks for your input on improving the navigation bar component. The changes look good on our end.

[fadeev]

@marinhoarthur can you, please, review, so we can merge if it looks good. Thanks!

[marinhoarthur]

closes #238