feat(tools): updated experiment infra to run experiemnts against Clickhouse using different strategies such as using materialized views, or using sketches

[milindsrivastava1997]

Summary

Issue #491 needs ClickHouse benchmarked using its own precompute mechanisms (sketch functions, materialized views, materialized views + sketches) as additional comparison arms against ASAPQuery, alongside the existing exact baseline and sketchdb arms. Each new arm needs different SQL (and in some cases a different schema) than baseline, not just a different protocol/server.

This PR lays the config plumbing for that:

• Adds mode constants for the 3 new arms: baseline_sketch, baseline_mv, baseline_mv_sketch (asap-tools/experiments/constants.py).
• generate_clickhouse_client_configs now resolves each query group's SQL per mode, inside the mode loop, instead of building one shared query list once and reusing it for every mode (which is why baseline and sketchdb always got identical queries today).
• sketchdb always resolves its SQL through the baseline entry — ASAP's SQL-mode planner needs to see the exact same SQL text as baseline to pattern-match it against available sketches; it can't understand ClickHouse-specific functions or MV-backed FROM clauses.

sql_file format change (breaking)

query_groups[i].sql_file is now a dict keyed by mode name instead of a single shared path, since each precompute arm may query different SQL/schema (e.g. baseline_mv reads from a materialized view instead of the raw table).

Old — one path shared by every mode:

query_groups:
  - name: default_queries
    sql_file: /path/to/baseline.sql

New — dict keyed by mode name:

query_groups:
  - name: default_queries
    sql_file:
      baseline: /path/to/baseline.sql
      baseline_sketch: /path/to/baseline_sketch.sql
      baseline_mv: /path/to/baseline_mv.sql
      baseline_mv_sketch: /path/to/baseline_mv_sketch.sql
      # no "sketchdb" key — it always resolves through "baseline"

For a baseline + sketchdb-only experiment (today's common case), the new format only needs a baseline entry:

query_groups:
  - name: default_queries
    sql_file:
      baseline: /path/to/baseline.sql

Existing local configs need to be updated to the dict format to keep working.

Out of scope (left for follow-up)

• The actual DDL (materialized views + target tables) and per-arm SQL query files