Add a hint to enable ExplicitNamespaces for type operator imports (Fixes/Enhances #20007)

As suggested in #20007 and implemented in !8895, trying to import type operators
will suggest a fix to use the 'type' keyword, without considering whether
ExplicitNamespaces is enabled. This patch will query whether ExplicitNamespaces
is enabled and add a hint to suggest enabling ExplicitNamespaces if it isn't enabled,
alongside the suggestion of adding the 'type' keyword.