feat(csharp/src/Drivers/Apache): Add escape underscore parameter to metadata command

[eric-wang-1990]

Add support for escaping underscores in metadata queries

Why

For current Power BI ODBC connection we are escaping all the underscore. I've thinking about change in the connector side to always pass in the escaped name, but it is not feasible since later we will introduce sql text based metadata query like DESCRIBE TABLE xxx as json, where we would expect xxx not be escaped since it will be treated as text.
Thus the best way is to introduce a new parameter in the metadata api to specify whether the client want to escape the underscore, then on the driver side based on different calling method(Thrift API or sql text) we can perform differently.

Description

This PR adds support for escaping underscores in metadata query parameters through a new parameter adbc.get_metadata.escape_underscore. When enabled, underscores in catalog, schema, table, and column names will be treated as literal characters rather than SQL wildcards.

Changes

• Added new parameter EscapeUnderscore to control underscore escaping behavior
• Added EscapeUnderscoreInName helper method to handle underscore escaping
• Updated all metadata query methods to use the escaping functionality:
  • GetCatalogsAsync
  • GetSchemasAsync
  • GetTablesAsync
  • GetColumnsAsync
  • GetPrimaryKeysAsync
  • GetCrossReferenceAsync
  • GetCrossReferenceAsForeignTableAsync

Testing

• Added test case in CanGetColumnsExtended to verify the escaping functionality
• Verified that null values are handled correctly
• Verified that escaping only occurs when the flag is enabled

Usage

To enable underscore escaping, set the parameter:

statement.SetOption(ApacheParameters.EscapeUnderscore, "true");

Impact

This change allows users to query metadata for objects that contain underscores in their names without the underscore being interpreted as a SQL wildcard character.

[CurtHagenlocher]

Thanks! Is it only the underscore that needs escaping or would a percent sign also need it? If the answer is "no", I'll commit the change.

[eric-wang-1990]

Thanks! Is it only the underscore that needs escaping or would a percent sign also need it? If the answer is "no", I'll commit the change.

Nope, if it needs it we need to introduce a new flag, but currently no for power bi odbc.