[Feature Request] Add active prop to NavLink

[AnnMarieW]

It would be great to have an active prop on NavLink similar to Dash Bootstrap Components

• dbc.NavLink docs
• dbc.Navlink GitHub

active (boolean | a value equal to: 'partial', 'exact'; default False): Apply 'active' style to this component. Set to "exact" to automatically toggle active status when the current pathname matches href, or to "partial" to automatically toggle on a partial match. Assumes that href is a relative url such as /link rather than an absolute such as https://example.com/link For example - dbc.NavLink(..., href="/my-page", active="exact") will be active on "/my-page" but not "/my-page/other" or "/random" - dbc.NavLink(..., href="/my-page", active="partial") will be active on "/my-page" and "/my-page/other" but not "/random".

This makes it possible to show which link in a menu or side panel is active regardless of how you navigate to the page.