More robust quoted names handling

[dvarrazzo]

Added a proper parser for a sequence of dot-separated quoted names.

Let quote_id do the merging back into dot-separated quoted names string, minimising the use of ad-hoc %s.%s where sometimes one side got unquoted.

[dvarrazzo]

Ugh, I see a lots of things are failing in the test: this MR requires more work. It was necessary though to handle the case of a db with foo."bar.baz" names (I can dump that db with this and other changes).

[jmafc]

@dvarrazzo Daniele, do you have a minimal test case? I presume it would first suffice to do a CREATE TABLE foo."bar.baz", but it seems we also should test CREATE TABLE "foo.bar"."Baz" and not just for tables (but we can start with schemas and tables).