[lldb/API] Add Breakpoint::SerializeToStructuredData to SBAPI

This patch adds a way to fetch breakpoint metadatas as a serialized
`Structured` Data format (JSON). This can be used by IDEs to update
their UI when a breakpoint is set or modified from the console.

rdar://11013798

Differential Revision: https://reviews.llvm.org/D87491



Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>