Factor out runner calls from pillar
    
    Runner execution causes pillar rendering to slow down significantly.
    Move hosts functions to regular execution module and call those instead
    (this works as execution module calls in the pillar are executed on the
    master as well).
    
    Example rendering of the pillar for witch1.i.o.o yielded total times of:
    - ~11 seconds before this patch
    - ~3 seconds after this patch
    
    Comparing the profiling logs showed specificially the pillar templates
    with runner calls to have contributed to the poor first result.
    
    The role.monitoring.master pillar still executes a runner due to a
    dependency on the Salt mine, this will require separate refactoring.
    This however only affects a single minion, all other minions will
    already benefit from the improvements here.
    
    Reference: https://github.com/saltstack/salt/issues/43163
    
    Signed-off-by: Georg Pfuetzenreuter <mail@georg-pfuetzenreuter.net>