Inline machineId and sessionId

* new experimentation service based on tas-client

* fixes for exp service

* add event classifications

* leverage product.json

_serviceBrand is only used for typing and should not result in emit

Also adds readonly

This change will filter DAP keys beginning with `!` when the remote
authority is "other", which SteVen recommended as a way to tell if we're
on web/codespaces.

Isidor mentioned previously that there was filtering for keys beginning
with an underscore, but this was only applied to some data in error
responses, not general telemetry events. An alternative approach to this
is filtering exceptions based on the environment on the extension side,
but I figured it would be better to have VS Code do that so that we
don't end up with N many possibly deviant sets of environment detection
logic.

* Added strictly typed telemetry function

* cleanup publicLog2 signature