sink: support cloud storage sink

[wk989898]

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[hongyunyan]

We can omit these two variables in the general newSink.

1. for pdClock, we can get directly by pdClock := appcontext.GetService[pdutil.Clock](appcontext.DefaultPDClock)
2. for errCh we can deal with as mysqlSink or KafkaSink

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Test name	Commit	Details	Required	Rerun command
pull-check	d7fa189	link	true	/test pull-check

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