added resource principal authentication and OCI fn wrapping function

[lodatol]

Added the possibility to use the scheduler as a function so it can be scheduled using resource scheduler directly from OCI Resource scheduler.

In order to allow the scheduler to invoke the function and the function to startup and close service a policy like the following must be added:
allow dynamic-group to manage all-resources in compartment <resources_compartment>
Allow any-user to use function-family in compartment <Function_Compartment> where all {request.principal.type='resourceschedule', request.principal.id=}

where DGResourceSchedulerFN is a Dynamic Group like this:
ALL {resource.type = 'fnfunc', resource.compartment.id = <Function_Compartment_OCID>}

and resource_compartment is the compartment that contains resources to be controlled by the script

Hope you find it useful