Add error output column to show Flint index statement

[dai-chen]

Description

This PR introduces a new output column, error, to display detailed root error messages when a Flint index is in a Failed state. The error column will only be included if the EXTENDED keyword is present in the SHOW FLINT INDEX statement, similar to the Spark SHOW TABLE EXTENDED statement.

The rationale behind this change is twofold:

1. The error message is only relevant when the index status is "Failed"; for others, the error field will be empty.
2. The error message can be lengthy, as it's collected from each Spark executor and currently truncated to 1000 characters, so they are returned only when needed.

Documentation

Updated user manual: https://github.com/dai-chen/opensearch-spark/blob/return-error-in-show-flint-index-statement/docs/index.md#all-indexes

Changes

1. Added a separate grammar rule to accommodate potential future differences in the extended statement. Ref: https://github.com/apache/spark/blob/branch-3.3/sql/catalyst/src/main/antlr4/org/apache/spark/sql/catalyst/parser/SqlBaseParser.g4#L168
2. Refactored the AST builder to eliminate duplicate code and improve maintainability.

Example

Tested with EMR-S:

"result": [
  "{
    'flint_index_name':'flint_glue_default_http_logs_skipping_index',
    'kind':'skipping',
    'database':'default',
    'table':'http_logs',
    'auto_refresh':false,
    'status':'unavailable'
  }",
  """{
    'flint_index_name':'flint_glue_default_http_logs_streaming_error_index',
    'kind':'covering',
    'database':'default',
    'table':'http_logs',
    'index_name':'streaming_error',
    'auto_refresh':true,
    'status':'failed',
    'error':'failure in bulk execution:\n
    [0]: index [flint_glue_default_http_logs_streaming_error_index], id [kqSSvJAB69S8YQePXjzu], message [OpenSearchException[OpenSearch exception [type=cluster_block_exception, reason=index [flint_glue_default_http_logs_streaming_error_index] blocked by: [FORBIDDEN/8/index write (api)];]]]\n
    [1]: index [flint_glue_default_http_logs_streaming_error_index], id [k6SSvJAB69S8YQePXjzu], message [OpenSearchException[OpenSearch exception [type=cluster_block_exception, reason=index [flint_glue_default_http_logs_streaming_error_index] blocked by: [FORBIDDEN/8/index write (api)];]]]\n
    [2]: index [flint_glue_default_http_logs_streaming_error_index], id [lKSSvJAB69S8YQePXjzu], message [OpenSearchException[OpenSearch exception [type=cluster_block_exception, reason=index [flint_glue_default_http_logs_streaming_error_index] blocked by: [FORBIDDEN/8/index write (api)];]]]\n
    [3]: index [flint_glue_default_http_logs_streaming_error_index], id [laSSvJAB69S8YQePXjzu], messag...'
  }"""
],
"schema": [
  "{'column_name':'flint_index_name','data_type':'string'}",
  "{'column_name':'kind','data_type':'string'}",
  "{'column_name':'database','data_type':'string'}",
  "{'column_name':'table','data_type':'string'}",
  "{'column_name':'index_name','data_type':'string'}",
  "{'column_name':'auto_refresh','data_type':'boolean'}",
  "{'column_name':'status','data_type':'string'}",
  "{'column_name':'error','data_type':'string'}"
],
...

Issues Resolved

#405

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