feat: Add match_action for plugin configs

[benjackwhite]

Problem

Just the migration part of https://github.com/PostHog/posthog/pull/22056

Changes

• Adds new match action field for plugins

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Does this work well for both Cloud and self-hosted?

How did you test this code?

[tiina303]

I'm not sure about the constraint failure for the migration 🤔

[posthog-bot]

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