Feature: give us the ability to skip scheduling pods whose scheduler name is set to default-scheduler

[NickrenREN]

For now, similar to kubernetes, scheduler name of godel scheduler can also be configured, users can select pods to be processed by godel scheduler by setting pod's spec.schedulerName

besides this, two types of pods will also be scheduled by godel scheduler:

• scheduler name is set to default-scheduler
• scheduler name is empty.

In order to avoid conflicts with kubernetes default scheduler, we can add a feature to give us the ability to skip scheduling default-scheduler pods.

[NickrenREN]

@Liumeng-lambert please take a look at this