Explanation:
Add new methods to the NodePrinter class, which allow children classes to track the range of various parts of the demangled, such as the name and parameters.

Scope:
The changes in this PR apply to the demangling mechanism and should be almost be NFC, as we are just refactoring code by making some methods virtual. We are also adding 2 new variants of an already existing API demangleSymbolAsString.

Issues:

Original PRs:

• [swift][Demangling][NFC] Move NodePrinter declarations to a header #82335
• add new methods to the NodePrinter to enable range tracking possibilities when demangling a name #82336

Risk:
Low, the changes are almost NFC.

Testing:
Built against the LLVM patches which add demangling syntax highlighting. I have tested debugging sample program and everything behaved as expected.

Reviewers:

• @adrian-prantl