This adds a history table for `iam_scope`. It also includes reusable
triggers to maintain the included history table and future history
tables.
This also includes a test suite that runs on any table ending in `_hst`.
This adds a SQL function that generates a secure random ID of at least
14 characters suitable for use as a public or private ID. IDs generated
with the function will only contain characters from the unreserved
character set defined in RFC 3986 Section 2.3 making them safe for use
in a URL.