[Feature][API] Add metadata changed event in api module when metadata changed

### Search before asking

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

### Description

We need to do some work once metadata changed in DS, e.g. lineage parser when workflow changed/task changed、workflow online notification、project delete notification...

It's better to expose these events in ds API module.

We can use `EventBus` to store these events, the default implementation can be memory, can only print these in log, user can easily add their event consumer.

### Use case

_No response_

### Related issues

_No response_

### Are you willing to submit a PR?

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

### Code of Conduct

- [x] I agree to follow this project's [Code of Conduct](https://www.apache.org/foundation/policies/conduct)

Start by locating the ds API module and its existing EventBus-related entry points. Determine which metadata changes must emit events and how consumers should receive them; the issue does not name files, tests, or a defined completion condition.

Written by the indexing model from the issue text.