SNOW-3266242: Support TRY_CAST with user-provided schema in DataFrameReader

[sfc-gh-yuwang]

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

   Fixes SNOW-3266242

2. Fill out the following pre-review checklist:

   • 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
   • I am adding new logging messages
   • I am adding a new telemetry message
   • I am adding new credentials
   • I am adding a new dependency
   • If this is a new feature/behavior, I'm adding the Local Testing parity changes.
   • I acknowledge that I have ensured my changes to be thread-safe. Follow the link for more information: Thread-safe Developer Guidelines
   • If adding any arguments to public Snowpark APIs or creating new public Snowpark APIs, I acknowledge that I have ensured my changes include AST support. Follow the link for more information: AST Support Guidelines

3. Please describe how your code solves the related issue.

   preiously try_cast is not supported when using user schema, this PR meant to fix this gap

[sfc-gh-aling]

why we need to introduce this new var?
was there a bug before?

[sfc-gh-yuwang]

technically there is a bug before,
in the analyzer: https://github.com/snowflakedb/snowpark-python/blob/main/src/snowflake/snowpark/_internal/analyzer/snowflake_plan.py#L1960
we need this bool value to actually apply try_cast to the result, otherwise try_cast is ignored

[sfc-gh-aling]

can you check with @sfc-gh-skumbham to understand the scope? is this requirement just for csv?
do we need generalization for other formats?

[sfc-gh-yuwang]

I have confirmed with him that this PR's scope is limited to CSV