Include module_name in all model admin views with breadcrumbs

[Marijke Luttekes]

Provide a context variable module_name to all model admin views that do not yet have this value, for consistency.

This value is a capitalized version of a model's pluralized verbose name, typically used in the third breadcrumb link that points to a changelist view.

Reasoning

As originally mentioned on the forum: ​Some potential bugs found when making custom admin pages.

Some model admin pages like the history view (template: ​object_history.html) provide a context variable module_name, which is used in the breadcrumbs block of the template.

Other templates, e.g., the add/edit view (template: ​change_form.html) do not provide this value as context data. Instead, they modify the object's verbose plural name in place within the breadcrumbs block.

Adding this value to all the relevant admin templates would make the code more consistent.

Python code

This is is how we build the module name in Python from a ModelAdmin instance:

opts = self.model._meta
module_name = str(capfirst(opts.verbose_name_plural))

Templates like change_form.html use this code instead:

{{ opts.verbose_name_plural|capfirst }}

[Marijke Luttekes]

I'm unassigning Vaibhav Pant because I was waiting for this ticket to be triaged before picking it up myself.

Please do not assign a ticket to yourself within a minute of its creation without discussion.

If, after triage, I'm unable to pick it up, I'll make a post here.