[CORE][UI] Fix fallback info for V2 writes and align plan with Spark SQL tab

[Zouxxyy]

What changes are proposed in this pull request?

Fix Gluten UI not displaying fallback info for V2 writes (e.g., Iceberg INSERT with sort order), and align the plan display with Spark SQL tab (consistent operator IDs, complete plan tree).

Root causes:

1. Plan traversal skips CommandResultExec and V2CommandExec, missing V2 write fallback reasons.
2. In AQE mode, per-stage events have partial plans with inconsistent operator IDs; last stage overwrites earlier ones.

Fix: Add CommandResultExec recursion in GlutenExplainUtils/GlutenImplicits/GlutenFallbackReporter. Add GlutenQueryExecutionListener that generates complete fallback data from the fully materialized QueryExecution after execution ends, posted as event for both live UI and History Server.

We also considered a listener-side merge approach (accumulating per-stage events), but it cannot produce consistent operator IDs or a complete plan tree.

How was this patch tested?

Added test in VeloxIcebergSuite. Verified on History Server.

before

after

Was this patch authored or co-authored using generative AI tooling?

Generated-by: Kiro (Claude Opus 4.6), co-authored with Zouxxyy through iterative design, code review, and testing.

[github-actions]

Run Gluten Clickhouse CI on x86

[github-actions]

Run Gluten Clickhouse CI on x86

[Zouxxyy]

CC @zhztheplayer @JkSelf @jinchengchenghh for a look, thanks