swift: Discovery API for VanadiumCore

Wraps the high-level scan/advertise discovery API using exported CGO
functions.  Uses JSON to marshal the advertising structs back and
forth since we don't yet have VOM.

Also fixes logging for VanadiumCore.

TODO: Support attachments.
Change-Id: I52766dddb7e4e490118db11e7e109b8073e82f9e
6 files changed
tree: 7cc907fd14dd1786f02d9cf0f54ec5c2dc9b807a
  1. impl/
  2. main/
  3. util/
  4. v23/
  5. .gitignore
  6. swift.go
  7. types.h