Add the ability to search/sort by logger name on the Flow run logs page

[znicholasbrown]

Why

Prefect core exposes hooks for logging non-Prefect specific logs to Cloud such as logs that would be from external libraries like boto3 and kubernetes. These logs are great for debugging and monitoring purposes. When visiting the logs page in the UI for a flow run it is easy to search based on the message of the log but it would be nice to either search or sort by the name of the logger itself.

For example:

February 26th 2020 at 1:03:56pm | prefect.CloudTaskRunner
Task 'reduce_task': finished task run for task with final state: 'Success'
---
February 26th 2020 at 1:03:58pm | distributed.deploy.adaptive
INFO Retiring workers [1]
---
February 26th 2020 at 1:04:02pm | dask_kubernetes.core
Deleted pod: dask-root-26896ee1-06s7h7

Without scrolling through all of the logs from my flow run it would be nice to be able to specifically look for the logs that come from the dask_kubernetes.core logger because they might provide some insight into the resource usage of my run.

What

A user would be able to visit the flow run's logs page to:

• [ ] filter logs based on the name of a logger used in their flow
• [ ] save only the logs from that specific logger

Notes

The core PR https://github.com/PrefectHQ/prefect/pull/2089 makes this more relevant because by default the DaskKubernetesEnvironment will now output some cluster autoscaling logs for users to provide visibility into their deployments.

(Moved from #1275 in old repo)