Added new functions to convert to/from a log level name (like `debug`)
to/from the equivalent `slog::Level::Debug`.
Signed-off-by: James O. D. Hunt <james.o.hunt@intel.com>
The agent logger is useful and generic enough that it can be used by
other components, so move the agent logging package to below a top level
`pkg` to encourage re-use.
Signed-off-by: James O. D. Hunt <james.o.hunt@intel.com>