Improve psql tab completion for views, FDWs, sequences and transforms

Improve psql tab completion for views, FDWs, sequences and transforms

The following improvements are done:
- Addition of type completion for ALTER SEQUENCE AS.
- Ignore ALTER for transforms, as the command is not supported.
- Addition of more completion for ALTER FOREIGN DATA WRAPPER.
- Addition of options related to columns in ALTER VIEW.

This is a continuation of the work done in 0cd6d3b.

Author: Ken Kato
Discussion: https://postgr.es/m/9497ae9ca1b31eb9b1e97aded1c2ab07@oss.nttdata.com