Add support for PGAdmin client

Currently, rocto does not support the PGAdmin PostgreSQL client. Since this is the widely used official PostgreSQL GUI client it should be supported.

TODO: Revise identifier (table name/column name) case conversion from uppercase to lowercase for consistency with PostgreSQL, which uses lowercase table and column names. This will require not just updating the conversion mechanisms from toupper to tolower, but also revising the auto upgrade logic to perform this conversion on all pre-existing nodes that use the uppercase format. (See also this discussion thread on !800 (merged).) As of this writing, the nodes in question that will require such updates are the following:

• ^%ydboctoocto("functions",functionname)
• ^%ydboctoocto("tables","octoOneRow")
• ^%ydboctoocto("tables","pg_catalog","pg_attribute",*)="|columnname|"
• ^%ydboctoocto("tables","pg_catalog","pg_class",)="tablename|"
• ^%ydboctoocto("tables","pg_catalog","pg_proc",)="functionname|"
• ^%ydboctoschema(tablename,"pg_attribute",columnname)
• any table name global
• ^%ydboctoxref(tablename)
• ^%ydboctoxref(tablename,columnname)