Allow certmonger create directories in a generic certificates directory

[WOnder93]

Expanding on my comment in #348, how about just extending miscfiles_manage_all_certs() with the create permission for dirs? (And removing the two new miscfiles_*_generic_cert_dirs() interfaces?)

[zpytela]

To recap: the current state is

allow certmonger_t cert_type:dir { add_name getattr ioctl lock open read remove_name search write };
allow certmonger_t cert_type:file { append create getattr ioctl link lock open read rename setattr unlink write };

There is a request for dir create and, based on the filename, there will be a rename requested later, too. The only existing superset is the manage interface.

[zpytela]

A new PR to modify existing an existing interface reflecting the current state: https://github.com/fedora-selinux/selinux-policy/pull/468

[zpytela]

Closing this PR in favor of https://github.com/fedora-selinux/selinux-policy-contrib/pull/356