[9.x] Add "addRestoreOrCreate" extension to SoftDeletingScope

[orange-alien]

I would like to suggest adding addRestoreOrCreate extenstion to the IlluminateDatabaseEloquentSoftDeletingScope.

Following exampels are assumed that User model use SofteDelete trait.

before this PR

• We need to check if user exists or not and do restore() or create().

$user = User::withTrashed()
    ->where(['email' => 'user@example.com'])
    ->first();

if($user) {
    $user->restore();
} else {
    $user = User::create([
        'email' => 'user@example.com',
        'name' => 'user name',
    ]);
}

after this PR

• We don't have to worry about if user exist or not.

$user = User::restoreOrCretae(
    ['email' => 'user@example.com'],
    ['name' => 'user name'],
);