IMPALA-14108: Add support for SHOW FILES IN table PARTITION for Iceberg

tables

This patch implements partition filtering support for the SHOW FILES
statement on Iceberg tables, based on the functionality added in
IMPALA-12243. Prior to this change, the syntax resulted in a
NullPointerException.

Key changes:
- Added ShowFilesStmt.analyzeIceberg() to validate and transform
  partition expressions using IcebergPartitionExpressionRewriter and
  IcebergPartitionPredicateConverter. After that, it collects matching
  file paths using IcebergUtil.planFiles().
- Added FeIcebergTable.Utils.getIcebergTableFilesFromPaths() to
  accept pre-filtered file lists from the analysis phase.
- Enhanced TShowFilesParams thrift struct with optional selected_files
  field to pass pre-filtered file paths from frontend to backend.

Testing:
- Analyzer tests for negative cases: non-existent partitions, invalid
  expressions, non-partition columns, unsupported transforms.
- Analyzer tests for positive cases: all transform types, complex
  expressions.
- Authorization tests for non-filtered and filtered syntaxes.
- E2E tests covering every partition transform type with various
  predicates.
- Schema evolution and rollback scenarios.

The implementation follows AlterTableDropPartition's pattern where the
analysis phase performs validation/metadata retrieval and the execution
phase handles result formatting and display.

Change-Id: Ibb9913e078e6842861bdbb004ed5d67286bd3152
Reviewed-on: http://gerrit.cloudera.org:8080/23455
Reviewed-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>
Tested-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>

common/thrift/Frontend.thrift

@@ -299,6 +299,10 @@ struct TShowFilesParams {
   // An optional partition set. Set if this operation should apply to a list of
   // partitions rather than the base table.
   2: optional list<list<CatalogObjects.TPartitionKeyValue>> partition_set
+
+  // File paths for Iceberg tables (and potentially other formats),
+  // pre-collected during analysis phase
+  3: optional list<string> selected_files
 }
 
 // Parameters for SHOW [CURRENT] ROLES and SHOW ROLE GRANT GROUP <groupName> commands