Enable Paths Grouping on backend

[neilkakkar]

Changes

Part of #4364

Goes after #6035

Decisions made:

1. Custom match regexes: * matches everything (.* regex). We don't allow custom regexes. We'll probably have to experiment to figure out what are the best operators to expose, but this seemed good enough for now.
2. The aggregation happens as early as possible: i.e. coming out from PathEventQuery. Doing things like this, start & end points respect aggregations as well, and felt cleaner than doing it in the middle, since that would involve keeping timestamps in order as well. (when 2 events become duplicates because of grouping, these effectively become duplicate events that we dedupe)

Introducing the path_groupings API parameter, which takes a list of strings to match. For example, see test:

posthog/ee/clickhouse/views/test/test_clickhouse_paths.py

Line 102 in 49b892b

def test_path_groupings(self):

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)

[EDsCODE]

Same as other comments. Mostly looks good. The PR description could use more detailing as to what parameters we're now able to use

Also, what's the difference between % and * you were describing above?

[neilkakkar]

Also, what's the difference between % and * you were describing above?

Based on: #4364 (comment) , decided to get rid of second operator.

The difference was: One did .*, like a true wildcard match, while the other, %, matched parts of URLs: [^?&=/]+

[EDsCODE]

Looks good