[1.x] Extract switch team logic into HasTeams trait

[chefe]

This PR extract the logic for team switching into the HasTeams trait, which allows to switch the current team from code.

Example: Use the switchTeam method to change the current team during a test.

/** @test */
public function xyz()
{
    $user = User::factory()->create();

    // ...

    $user->switchTeam($otherTeam);

    // ...
}