[Fleet] Extend Agent policy descriptions dynamically.

[WiegerElastic]

Describe the feature:
Have the dropdown of Agent Policies extended dynamically based on the content.

Describe a specific use case for the feature:

Before 8.13.0, the description of Agent policies was straightforward and extensive. As of 8.13.0, there has been an UI change that decreases the allowed characters per description it seems. If I hover over a policy, I receive the full description. This really breaks a workflow as you need to wait 1-2 seconds before the description shows up.

Example:

8.12.2.

This gives me all the information I need to select policies.

8.13.0.

This is not really ideal, if you have multiple policies starting with the same name prefix, as shown in the example.

cc @juliaElastic

[elasticmachine]

Pinging @elastic/fleet (Team:Fleet)

[juliaElastic]

Got a tip on eui channel: add css={{ minWidth: "300" }} to that EuiSelectable to increase the width