fix(snowflake): update describeTableQuery to use Snowflake's DESCRIBE TABLE

[sabinevidal]

Pull Request Checklist

• [ ] Have you added new tests to prevent regressions?
• [ ] If a documentation update is necessary, have you opened a PR to the documentation repository?
• [ ] Did you update the typescript typings accordingly (if applicable)?
• [x] Does the description below contain a link to an existing issue (Closes #[issue]) or a description of the issue you are solving?
• [ ] Does the name of your PR follow our conventions?

Description of Changes

Updates Query generation for Snowflake to use DESCRIBE TABLE as SHOW FULL COLUMNS FROM is unsupported by Snowflake. Also updates the result parsing logic to align with the column names and formats returned by Snowflake.

Closes #15525

Improvements to Snowflake query generation:

• packages/snowflake/src/query-generator-typescript.internal.ts: Modified the describeTableQuery method to use the DESCRIBE TABLE command and properly handle table schema extraction.

Enhancements to query result parsing:

• packages/snowflake/src/query.js: Updated the result parsing logic in the SnowflakeQuery class to align with the new column names and formats returned by Snowflake, ensuring accurate mapping of field properties.

List of Breaking Changes