It is sometimes necessary to defer initialization steps until the first actual usage
or until certain prerequisites have been met. For example, policy setting and
policy source registration should not occur during package initialization.
Instead, they should be deferred until the syspolicy package is actually used.
Additionally, any errors should be properly handled and reported, rather than
causing a panic within the package's init function.
In this PR, we add DeferredInit, to facilitate the registration and invocation
of deferred initialization functions.
Updates #12687
Signed-off-by: Nick Hill <mykola.khyl@gmail.com>
