SNOW-2372025: fix upper cased schema string parse

[sfc-gh-aling]

1. Which Jira issue is this PR addressing? Make sure that there is an accompanying issue to your PR.

   Fixes SNOW-2372025

custom schema string like NUMBER(12,3), TEXT(146) will fail because the previous implementation (regex pattern) is case sensitive

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   • I am adding a new automated test(s) to verify correctness of my new code
     • If this test skips Local Testing mode, I'm requesting review from @snowflakedb/local-testing
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   • I am adding a new dependency
   • If this is a new feature/behavior, I'm adding the Local Testing parity changes.
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3. Please describe how your code solves the related issue.

   Please write a short description of how your code change solves the related issue.