Add Event Log summary to Task/Dag Overview tabs

### Description

@o-nikolas @vincbeck

During the town hall meeting - it was brought up that important scheduler events in the Event Tab may not be easily visible or discoverable, with folks used to looking at the task logs.

One idea, was to have a count of Event Logs associated with a particular task run - e.g. `[Event Logs (5)]`

### Use case/motivation

_No response_

### Related issues
https://github.com/apache/airflow/pull/40967
https://github.com/apache/airflow/pull/40867

### Are you willing to submit a PR?

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

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)

Start by reviewing the related pull requests and locating the Task Overview, DAG Overview, and Event tabs in Airflow. Trace how event logs are associated with a task run, then confirm that the relevant overview tabs display an event-log count and that the count matches the available event logs.

Written by the indexing model from the issue text.