[Enhancement] set TerminationGracePeriodSeconds with config value in be.conf

### Search before asking

- [x] I had searched in the [issues](https://github.com/apache/doris-operator/issues?q=is%3Aissue) and found no similar issues.

### Description

Pod's `TerminationGracePeriodSeconds` are set by operator for dcr BEs, but absent for ddc compute group BEs.

### Solution

Like what is done for dcr BE statefulset creation, `TerminationGracePeriodSeconds` can be added to CG's statefulset definition with config value `grace_shutdown_wait_seconds` set in be.conf

### Are you willing to submit PR?

- [x] Yes I am willing to submit a PR!

### Code of Conduct

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