[BUG] score cannot be used in field name

[dai-chen]

What is the bug?
Field with score is not supported and causing fallback to legacy query processing.

How can one reproduce the bug?
N/A (Fallback will occur as if the query is handled properly. However if any new feature in v2 used, the legacy code throws exception)

What is the expected behavior?
score can be present in index or field name.

What is your host/environment?

• OS: OpenSearch 2.2
• Plugins: SQL

Do you have any screenshots?
N/A

Do you have any additional context?
Code related: https://github.com/opensearch-project/sql/blob/main/sql/src/main/antlr/OpenSearchSQLIdentifierParser.g4#L60

[acarbonetto]

@dai-chen This can be closed as part of #1456.