Add process ancestry data to trace2 on macOS to match what we
already do on Linux and Windows. Also adjust the way Windows
implementation reports this information to match the other two.
* mc/tr2-process-ancestry-cleanup:
t0213: add trace2 cmd_ancestry tests
test-tool: extend trace2 helper with 400ancestry
trace2: emit cmd_ancestry data for Windows
trace2: refactor Windows process ancestry trace2 event
build: include procinfo.c impl for macOS
trace2: add macOS process ancestry tracing