Attempt to support Statamic v4

[grantholle]

Here's a half-attempt to support Statamic v4.

I've got the tests somewhat passing, admittedly jumping a few versions of testbench. Statamic's APIs seem to have changed too, so I did my best to get things working. I'm not familiar enough with it to get much further.

When I try to perform the action in Statamic, the following error occurs:

Call to undefined method Statamic\\Structures\\CollectionTree::page() at duplicator/src/Actions/DuplicateEntryAction.php:115)

I see that in the Tree class there is a pages() function, but indeed no page(). I think it's close? Not sure.

[duncanmcclean]

Thanks! I'll take a look at fixing the tests & the bug you spotted when I have some time (likely not until tomorrow).

[duncanmcclean]

Thanks for this!

I've fixed the test & copied across changes made in the Core version of this action (the one used for non-multi-sites).

[duncanmcclean]

Released as part of v4.0.0.

[dominikfoeger]

Thanks for the super fast update! Is there a reason php >=8.2 is required?
Laravel 10 supports php >=8.1, would that be fine too?

[duncanmcclean]

Ah, didn't realise this PR removed PHP 8.1 support. I've added it back in v4.0.1.