This PR makes all errors in the agent panel to use the `Callout`
component instead of toasts. Reason for that is because the toasts
obscured part of the panel's UI, which wasn't ideal. We can also be more
expressive here with a background color, which I think helps with
parsing the message.
Release Notes:
- agent: Improved how we display errors in the panel.
Previously, upon getting close to reaching the context window, we'd just
suggest creating a new thread using the summary of the current one. Now,
we also suggest turning burn mode on as an alternative action to solve
the context window problem.
Release Notes:
- agent: Added a suggestion to turn burn mode on when getting close to
the context window limit.
What motivated me to refactor this component was the fact that I wanted
a new variant to allow having _two CTAs_ instead of just one. This
variant should work with either a single or multiline description. But,
given we were using a `Callout::single_line` and `Callout::multi_line`
API, I'd then need to have both `Callout::single_line_one_button` and
`Callout::single_line_two_buttons` type of variants, which just points
to a combinatorial problem.
With this refactor, the Callout now follows the same structure of the
Banner component, where it's all `Callout::new` and every method is
passed as if they were props in a React component, allowing for a more
flexible design where you can customize button styles. Also made it
slightly more robust for wrapping and removed the top border as that
should be defined by the place it is being used in.
Release Notes:
- N/A
