CRM-20927 - civicrm_menu - Add generic column for other data

CRM-20927 - civicrm_menu - Add generic column for other data

Background
==========

We need a place to store per-page information about IDS configuration.

More generally, as we continue adding features through extensions, we should
anticipate that the route metadata will expand in ways that we can't
anticipate.  Adding a general-purpose serialized field will help us define
new behaviors through extensions.

Before
======

All metadata in the routing table (`civicrm_menu`) had to stored in a
separate SQL column.

After
=====

Any unrecognized fields will be stored and loaded from the column
`module_data`.