Drift detection for views

A second `dbt run` with views fails because the view already exists. Flink does not support `CREATE OR REPLACE VIEW` so we can decide to support this by either:
1. Check if view exists and always force recreate with `ALTER VIEW` (unlike tables, views are not stateful, so should be safe)
2. Check if view exists, then check if any changes are detected, skip if no, recreate with `ALTER VIEW` if yes

We should give some thought to the UX, we also have the option to match existing pattern or diverge:
1. Match: Fail when detecting changes and require a special cli arg to opt-in to recreating views
2. Diverge: Assume recreating views is safe and proceed without any opt-in cli arg

No file, test, or entry point is named in the issue. Start by locating the existing view materialization and drift-check path, then clarify whether unchanged views should be skipped and whether recreation requires a CLI opt-in; done means repeated runs and changed views follow the chosen behavior.

Written by the indexing model from the issue text.