Issue #20264 stash some first pass code here for later.
Merge branch '20266' into 20264

Conflicts:
	lib/orm/source/xt/javascript/data.sql
Issue #20264 Add datasource pg listeners for INFO, NOTICE, WARNING messages from plv8.
Issue #20264 move debug notices to XT.debug.
Add example get request.
Stashing in progress code for later.
Issue #20264 Fix merge conflict.
Issue #20264 Add support for raising FATAL errors.
Issue #20264 use XT.debug
Issue #20264 Add config option to bubble debug message from db up to client.
stash
stash
stash
Issue #20264 moving away from FATAL erros.
Issue #20264 Move try/catch to highest level functions only.
Issue #20264 Restrict to only exposed functions.
Issue #20264 Remove try/catch from low level functions.
Issue #20264 Add success 2xx codes to 4 main verbs.
Issue #20264 Finish error handler.
Issue #20264 This is how we handle expected errors.