Transformations: Focus search input on drawer open

[codeincarnate]

What is this feature?

When adding transformations there is a search box which can be used to filter transformations. Currently this isn't focused when the drawer is opened causing an extra click. While auto-focusing on fields is generally not considered the best for accessibility when the drawer is open this field in the only text field which can be interacted with. In this case that seems like a reasonable trade-off.

Why do we need this feature?

It streamlines the addition of new transformations.

Who is this feature for?

Users of transformations.

Special notes for your reviewer:

Please check that:

• It works as expected from a user's perspective.
• If this is a pre-GA feature, it is behind a feature toggle.
• The docs are updated, and if this is a notable improvement, it's added to our What's New doc.