Add lazy version of admin_static's static
|Patch needs improvement:
To be CDN-friendly (with hashed static file names) it's important to run form assets through the static templatetag to get the correct filename. This can be done via django.contrib.admin.templatetag.admin_static.static, but if any chain of imports leads to static being invoked during a management command when the staticfiles are inaccessible (e.g. before collectstatic is performed) then it will fail to find the file and the command will error.
Lazy version can be used in these situations to lazily get the correct filename for form assets so that it is not resolved during management commands.