NavSingleItem: Allow setting a target attribute to an external item

[cstuder]

Sample from _nav.js:

bottom: [
    {
      name: 'Get Vibe',
      url: 'https://github.com/NiceDash/Vibe',
      icon: 'GitHub',
      external: true,
      target: '_blank'
    }

I would keep it as an option and not link to external items with a _blank target as default.

[julians300]

Great idea :)

Consider adding your example to _nav.js as well.

[cstuder]

I will try.

There's an additional security problem with target="_blank" requiring rel="noopener" as well (See https://mathiasbynens.github.io/rel-noopener/).

Additionally maybe a refactoring could also drop the requirement of adding external=true when putting an absolute URL as parameter.

[cstuder]

Updated, what do you think?

[julians300]

Looks great! Thanks!