Add helper to show CRUD history for particular object

[kirmalyshev]

Issue: #192
How to use:

1. Inherit your ModelAdmin class from CRUDHistoryAdminMixin
2. use filed crud_history_link in list_display, or in fieldsets

Example in code

class SomeModelAdmin(CRUDHistoryAdminMixin):
    list_display = (
        "id",
        "crud_history_link",
    )

[kirmalyshev]

@soynatan Did you review this PR? Maybe, you have some fix requests?

[kirmalyshev]

Wanted to check -- is the PR needed? Or should I close it?

[jheld]

Sounds like the intention is to make integration with linking to crud history inside the admin more easy, so that's a positive.