[11.x] Allow enums to be passed to AssertableJson where methods

[patrickomeara]

Like a lot of developers, I hate strings. Strings are for users.

Enums give me type safety for speling mistakes, and generally make me feel more comfortable about the world and my code.

This PR brings the where, whereNot and whereContains methods of the AssertableJson class in to line with their Eloquent cousins by accepting enums.

This change is backward compatible.

$this->getJson('/users/1')
    ->assertJson(fn (AssertableJson $json) => $json->where('role', UserRole::Developer->value))

// becomes
$this->getJson('/users/1')
    ->assertJson(fn (AssertableJson $json) => $json->where('role', UserRole::Developer))

[driesvints]

Please rebase so tests pass, thanks!

[cosmastech]

Strings are for users.
🔥