Show search bar for plugin config choice field

[yakkomajuri]

Changes

Allows searching through a plugin's config options. This will be important for plugins with a lot of choices available

Checklist

• All querysets/queries filter by Organization, by Team, and by User
• Django backend tests
• Jest frontend tests
• Cypress end-to-end tests
• Migrations are safe to run at scale (e.g. PostHog Cloud) – present proof if not obvious
• New/changed UI is decent on smartphones (viewport width around 360px)

[yakkomajuri]

This is such a tiny change but just to follow best practice I feel bad merging without a reviewer :D

Tagging you @mariusandra given @Twixes is off.

[Twixes]

Deliciously simple :)