Multiple APM errors per transaction id

**Is your feature request related to a problem? Please describe.**
Sometimes there may be multiple errors within a service that are related to a transaction. It is hard to know if one error may have other errors that are related to it i.e. the current error may not be the root cause / the real issue. You cannot view the transaction id in the 'metadata' and have to view the logs in Discover to find a transaction id. Once you have the transaction id you can then search the Service's Errors to find any matching errors.

In this case one error is the root cause and the other error was caused by this error.

**Describe the solution you'd like**
It would be ideal to know if one Error may be related to another Error (i.e. within the same transaction) on the Error details page. Ideally there would be a link to other possibly related errors. It would be nice to have the transaction.id accessible on the Error details page.

I appreciate that there would be lots of transactions which relate to an Error which makes this more complex.

Ideally the minimum solution would be displaying the, transaction.id and some text suggesting there are other errors for the currently sampled transaction.