feat(hogql): query modifiers

[mariusandra]

Problem

We want the ability to enable/disable optimisations in HogQL as needed, including specifying them on the client side to shorten the feedback loop.

Changes

• Introduces a central HogQLQueryModifiers interface that can be appended to a HogQLQuery node to specify the behaviour of query features.
• Introduces a central modifiers.py -> create_default_modifiers_for_team for setting modifiers automatically
• Moves personsOnEventsMode to the modifiers (camelCased python? 🤔 🤷)
• Introduces the PoE option in the /debug endpoint

Next steps

• Newer persons query join as the next modifier
• The C++ parser as another modifier
• Hooking this up to feature flags to enable/disable features for users like ✨🌈💖
• Benchmarks that measure queries with the modifier on and with it off

How did you test this code?

Wrote tests. In the future all modifiers should get their own tests under test_modifiers.py