feat(data-exploration): HogQL refactor, events list filters

[mariusandra]

Problem

Bringing over a few refactors from #13264

Changes

• Rename ExprParserContext to HogQLContext, and expr_parser.py to hogql.py
• Add type: 'hogql' property filters
• Make these filters work in the events table (passed hogql context to parse_prop_grouped_clauses)
• Rename BreakdownFilter to TaxonomicBreakdownFilter to align with the filename
• Improve inline query editor placeholder with helpful hints

How did you test this code?

• Wrote tests for the events endpoint
• Added filters manually in the interface

[thmsobrmlr]

LGTM

[mariusandra]

Thanks! This seems safe enough to get in, so going to merge. Work is actively ongoing, and I'm happy to address any new feedback in #13806 or other followups.