Not used in coderd yet, see stack.
Adds two new packages:
- `coderd/usage`: provides an interface for the "Collector" as well as a stub implementation for AGPL
- `enterprise/coderd/usage`: provides an interface for the "Publisher" as well as a Tallyman implementation
Relates to https://github.com/coder/internal/issues/814
PProf labels segment the code into groups for determing the source of
cpu/memory profiles. Since the web server and background jobs share a
lot of the same code (eg wsbuilder), it helps to know if the load is
user induced, or background job based.
Steven Masley