Integrate `public_callback`from `dash_auth` into `dash_extensions.enrich`

[nils-fl]

Hi there,

I love dash_extensions! It makes some of my pages blazing fast. When I use dash_auth I sometimes have to whitelist public routes and I have to use public_callback from dash_auth. The problem is, that I have to go back to read/load json, which slows the public pages down again.

Would it be possible to integrate public_callback from dash_auth into dash_extensions.enrich? It would be awesome to use Serverside() in a public_callback!

Best Nils