feat(hogql): time to convert funnel

[thmsobrmlr]

Problem

Funnels need to be converted to HogQL (see the funnels section in PostHog/meta#130).

Changes

• Adds support for time-to-convert funnels, thereby also.
• Adds hogql support for "least" and "greatest" functions.
• Explicitly types funnel results.

Things that aren't as nice as they could be

• The clickhouse query explodes, as aliased tables get inlined (see snapshots).
• The query was refactored to use a JOIN ON ... instead of a JOIN USING ..., as HogQL doesn't support USING yet and I wanted to get this over the line.

How did you test this code?

Converted existing tests for the HogQL implementation

[github-actions]

Size Change: +221 B (0%)

Total Size: 2.22 MB

ℹ️ View Unchanged

Filename	Size	Change
frontend/dist/toolbar.js	2.22 MB	+221 B (0%)

_{compressed-size-action}

[posthog-bot]

📸 UI snapshots have been updated

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

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

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

Triggered by this commit.

👉 Review this PR's diff of snapshots.