Add support for related ManyToMany fields

[yuekui]

_clone_many_to_many_fields now could be used for both many to many and related fields:

class Author(CloneModel):
    first_name = models.CharField(max_length=200, unique=True)
    last_name = models.CharField(max_length=200)

class Book(CloneModel):
    name = models.CharField(max_length=2000)
    authors = models.ManyToManyField(Author, related_name="books")

    _clone_many_to_many_fields = ["authors"]

or

class Author(CloneModel):
    first_name = models.CharField(max_length=200, unique=True)
    last_name = models.CharField(max_length=200)

    _clone_many_to_many_fields = ["books"]

class Book(CloneModel):
    name = models.CharField(max_length=2000)
    authors = models.ManyToManyField(Author, related_name="books")

[jackton1]

@yuekui Can you add a description of why we need this change . I'm curious to know the use case. Thanks

[yuekui]

@yuekui Can you add a description of why we need this change . I'm curious to know the use case. Thanks

Hi @jackton1 thanks for you attention, I just added a simple example in #190 , I hope it could help