query to support synonyms

A useful SQL feature is to assign synonyms to tables.
This is in particular useful to access tables external to the current database.
N1QL should have the same, in particular to access collections outside of the current query context.
Synonyms to collections are straight forward, but attention should be paid to how, or even if, to implement global synonyms (to use UDF parlance) (ie synonyms sitting at the bucket level).

This improvement requires metadata storage.