CDB: Make use of the improved debugger expression syntax

CDB can now handle sizeof(Class) and even expressions that
determine the offset of map node values (to some extent), may still
fail with templates). Format expressions accordingly, adapt
cached expressions.
Use gdbQuoteType depending on debugger type only.
Most important, do not evaluate each expression separately before
issuing the call, as ".call" can now do it on its own. Check for syntax
errors there and cache failing types as before.