pid1: rename manager_get_show_status() to manager_should_show_status()

The name 'manager_get_show_status()' suggests that the function simply reads
the property 'show_status' of the manager and hence returns a 'StatusType'
value.

However it was doing more than that since it contained the logic (based on
'show_status' but also on the state of the manager) to figure out if status
message could be emitted to the console.

Hence this patch renames the function to 'manager_should_show_status()'. The
previous name will be reused in a later patch to effectively return the value
of 'show_status' property.

No functional change.