WL#7202: True bottom-up server parser: refactoring of the DELETE and TRUNCATE statements

Status: Complete

This WL is intended to refactor DELETE and TRUNCATE statement-related parser
grammar rules in a pure bottom-up style to make it (grammar) context-independent
for the better maintainability and extendability at the first place.

This WL uses the framework and the methodology of the refactoring from the
WL#7199 "True bottom-up server parser: common framework for the refactoring".

The WL depends on the similar WL#7200 for the SELECT statement since that WL
covers the refactoring of "expr", "subselect" etc common rules.