title: Django model aggregate matches count in ManyToMany
body: <p>There is Model with ManyToMany field:</p>
  
  <pre><code>class Number(Model):
      current_number = IntegerField()
  
  class MyModel(models.Model):
      numbers_set = models.ManyToMany(Number)
  </code></pre>
  
  <p>For example we have such dataset:</p>
  
  <pre><code>my_model_1.numbers_set = [1, 2, 3, 4]
  my_model_2.numbers_set = [2, 3, 4, 5]
  my_model_3.numbers_set = [3, 4, 5, 6]
  my_model_4.numbers_set = [4, 5, 6, 7]
  my_model_5.numbers_set = [4, 5, 6, 7]
  </code></pre>
  
  <p>I'm looking for a way to aggregate MyModel by amount of same numbers.</p>
  
  <p>f.e. MyModel objects that have at least 3 same numbers in theirs numbers_set.</p>
  
  <pre><code>[
      [my_model_1, my_model_2],
      [my_model_2, my_model_3],
      [my_model_3, my_model_4, my_model_5],
  ]
  </code></pre>