Nested CRUDs example

[tabacitu]

This PR includes a new demo entity, "Snippets", which can be manipulated through the sidebar entries:

• All Snippets - regular CRUD for the Snippets model;
• My Snippets - extends the regular SnippetCrudController to only show the logged in person's snippets;
• Creator Snippets - nested CRUD - shows the snippets of a certain user (aka Creator);

We could include this in the main demo. We could. But in my opinion it adds quite a few more components, just to test one thing - that Nested CRUDs work. Food for thought...

[srigurubyo]

I am looking to run this sample but some of the functions are deprecated in new version (ex: str_limit()).

Can you please help me with the relationship_count.blade.php particularly as I am not very well versed in php coding.

Thanks!

[tabacitu]

str_limit() should be replaced with Str::limit() as per Laravel 7 requirement - the others should be similar.

Sorry @srigurubyo this is not a priority, so it won't get any attention soon. Happy to merge PRs into this if anybody fixes it for Backpack 4.1.