runtime: Enable print calls

This commit enables print() calls inside of the server for INFO and
DEBUG log levels. The print hook is plumbed through to the server via
the manager so that other server implementations (e.g., the Envoy
plugin) can be updated similarly.

The server will compile print() calls for the /v1/query API but not
others since (i) print() calls inside the policies will already have
been compiled and (ii) the queries are limited to fetching `data`
paths and therefore cannot contain print() calls themselves. The
bundle plugin has been updated to compile print() calls as well--this
way the bundle plugin/server will respect incoming bundles and not
attempt to override them.

Signed-off-by: Torin Sandall <torinsandall@gmail.com>