Invulnerable players cannot shrink or grow

[Clemcarle]

• Depends on Create "invulnerable" status #381

When a player is invulnerable, they should not shrink upon collision with another player.

#ifdef FIX_ISSUE_382
  ///An invulnerable player cannot shrink
  {
    game g;
    
    //Make the first player invulnerable
    become_invulnerable(g.get_player(0));
    
    // Make player 1 and 2 overlap
    g.get_player(1).set_x(g.get_player(0).get_x());
    g.get_player(1).set_y(g.get_player(0).get_y());
    assert(has_collision(g));
    
    // After a tick, invulnerable player does not shrink
    const int inv_player_size_before =  get_nth_player_size(g, 0);
    g.tick();
    const int inv_player_size_after =  get_nth_player_size(g, 0);
    assert(inv_player_size_after == inv_player_size_before);
  }
#endif

[EvoLandEco]

An invulnerable player should have no clip with others, thus no grow either