ServerDdlExecutor cannot execute DROP commands with qualified object names

Consider the query DROP TABLE s.t. The ServerDdlExecutor will attempt to resolve the default schema path, and the would try to invoke SqlIdentifier.getSimple on the s.t identifier. When assertions are enabled this would lead to an AssertionError. When assertions are disabled this would lead to an incorrectly resolved table name: s instead of t.

All DROP commands are affected.