entcertlib docstring cleanup
reorder methods in roughly exec order
Add more entcertlib class and method docs.
CertSorter syncs installed prods before super init.

This reverts part of d0ea9f4040de7b3f917d2721c4b67e34fce73b6c
and returns a bug fix for #1004893

ComplianceManager's init needs the installed product info
to be synced to server before populating compliance status
info correctly. So do that.

Also let update_product_manager require cp_provider and
identity as late as possible.