feat: Add plugin config filtering

[benjackwhite]

Problem

Users don't want or need to create actions to setup a destination. If I come to PostHog and think "I wan't to get a slack message whenever someone performs X" then we should offer an inline way of doing this with actions simply being a possible filter.

Changes

• Adds a filters property to a plugin config
• Removes uses of match_action instead just using the standard action format
• Updates ActionWebhookFormatter to just be WebhookFormatter with a new source property for the source of the webhook
• Updates bits of logic we need to actually do this filtering.
• All of this is flagged and only applicable to the "special" plugin so should be safe to test with.

TODO

• Add some django validation of filters
• Outstanding todo in run.ts about plugin config name - it isn't on the type...

👉 Stay up-to-date with PostHog coding conventions for a smoother review.

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

How did you test this code?

[posthog-bot]

📸 UI snapshots have been updated

3 snapshot changes in total. 0 added, 3 modified, 0 deleted:

• chromium: 0 added, 3 modified, 0 deleted (diff for shard 1, diff for shard 2)
• webkit: 0 added, 0 modified, 0 deleted

Triggered by this commit.

👉 Review this PR's diff of snapshots.

[posthog-bot]

📸 UI snapshots have been updated

2 snapshot changes in total. 0 added, 2 modified, 0 deleted:

• chromium: 0 added, 2 modified, 0 deleted (diff for shard 2)
• webkit: 0 added, 0 modified, 0 deleted

Triggered by this commit.

👉 Review this PR's diff of snapshots.

[posthog-bot]

📸 UI snapshots have been updated

1 snapshot changes in total. 0 added, 1 modified, 0 deleted:

• chromium: 0 added, 1 modified, 0 deleted (diff for shard 2)
• webkit: 0 added, 0 modified, 0 deleted

Triggered by this commit.

👉 Review this PR's diff of snapshots.

[posthog-bot]

📸 UI snapshots have been updated

1 snapshot changes in total. 0 added, 1 modified, 0 deleted:

• chromium: 0 added, 1 modified, 0 deleted (diff for shard 2)
• webkit: 0 added, 0 modified, 0 deleted

Triggered by this commit.

👉 Review this PR's diff of snapshots.

[posthog-bot]

📸 UI snapshots have been updated

3 snapshot changes in total. 0 added, 3 modified, 0 deleted:

• chromium: 0 added, 3 modified, 0 deleted (diff for shard 1, diff for shard 2)
• webkit: 0 added, 0 modified, 0 deleted

Triggered by this commit.

👉 Review this PR's diff of snapshots.

[posthog-bot]

📸 UI snapshots have been updated

3 snapshot changes in total. 0 added, 3 modified, 0 deleted:

• chromium: 0 added, 3 modified, 0 deleted (diff for shard 1, diff for shard 2)
• webkit: 0 added, 0 modified, 0 deleted

Triggered by this commit.

👉 Review this PR's diff of snapshots.

[posthog-bot]

📸 UI snapshots have been updated

1 snapshot changes in total. 0 added, 1 modified, 0 deleted:

• chromium: 0 added, 1 modified, 0 deleted (diff for shard 2)
• webkit: 0 added, 0 modified, 0 deleted

Triggered by this commit.

👉 Review this PR's diff of snapshots.

[posthog-bot]

📸 UI snapshots have been updated

1 snapshot changes in total. 0 added, 1 modified, 0 deleted:

• chromium: 0 added, 1 modified, 0 deleted (diff for shard 2)
• webkit: 0 added, 0 modified, 0 deleted

Triggered by this commit.

👉 Review this PR's diff of snapshots.

[posthog-bot]

📸 UI snapshots have been updated

3 snapshot changes in total. 0 added, 3 modified, 0 deleted:

• chromium: 0 added, 3 modified, 0 deleted (diff for shard 1, diff for shard 2)
• webkit: 0 added, 0 modified, 0 deleted

Triggered by this commit.

👉 Review this PR's diff of snapshots.

[posthog-bot]

📸 UI snapshots have been updated

2 snapshot changes in total. 0 added, 2 modified, 0 deleted:

• chromium: 0 added, 2 modified, 0 deleted (diff for shard 1)
• webkit: 0 added, 0 modified, 0 deleted

Triggered by this commit.

👉 Review this PR's diff of snapshots.