feature: Support href in tabs

[zZHorizonZz]

Description

I think it might come in handy if there was support for href in primary/secondary tabs(You can wrap the tab in <a> obviously but then that actual tab won't work inside of md-tab component). This might be particularly useful for SSR situations. Currently, if you want to navigate to a different page, you need to do it manually through code.

[christophe-g]

@zZHorizonZz - see #4942. It was a feature request moved to discussion.

I have my own override for this. I can share if this is useful.