MB-16181: Make server deny creation of reserved collections

MB-16181: Make server deny creation of reserved collections

The design has always stated that _ and $ would be reserved for
system use. Make sure the server enforces this by checking the
names on incoming manifests.

1. Any _ prefixed collection will cause the Manifest construction to
 throw invalid_argument.

2. Any $ prefixed collection which is not $default will cause the
 Manifest construction to throw invalid_argument.

Change-Id: I1e5daf2ae87cba2a8dbcdda4c9bb0be66e40ffae
Reviewed-on: http://review.couchbase.org/78074
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>
Reviewed-by: Dave Rigby <daver@couchbase.com>
Tested-by: Build Bot <build@couchbase.com>