TiCDC openapi v2 support downstream ca cert key data not filepath

[cchenkey]

Is your feature request related to a problem?

No

Describe the feature you'd like

https://docs.pingcap.com/zh/tidb/stable/ticdc-sink-to-kafka

Currently, ticdc's creation of changefeed supports specifying the CA certificate paths for Kafka and MySQL to use. In practical scenarios, it may be more convenient to create changefeed by passing in certificate data, so there is no need to create certificate files on the storage disk of ticdc.

Describe alternatives you've considered

it may be more convenient to create changefeed by passing in certificate data, so there is no need to create certificate files on the storage disk of ticdc.

Teachability, Documentation, Adoption, Migration Strategy

I think a parameter for passing CA certificate data should be added to openapi v2, based current parameter.

[CharlesCheung96]

For other sinks, it is also reasonable to pass tls configuration by parameter, since the changefeed should not be affected by the deployment behavior.