To make the existing mechanism for printing JSON for turbolizer able to
print types other than the ones stored in the nodes (so the verifier can
print its own types here), this CL restructures the printing mechanism
into a single non-private class that can be inherited to override
certain parts of the printing. In this CL only GetType is made virtual
to allow verifier to override it, but additional parts can be made
overridable whenever necessary.

Bug: v8:12619
Change-Id: Idf31f8cdb49eb6c3204c6abfbb74fc981330d6d2
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3571818Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Nico Hartmann <nicohartmann@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79909}