SIT-2192 Add a new overload for `com.snowflake.snowpark.functions.round` function

[sfc-gh-fgonzalezmendez]

Please answer these questions before submitting your pull requests. Thanks!

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

   Fixes SIT-2192

2. Fill out the following pre-review checklist:

   • [X] I am adding a new automated test(s) to verify correctness of my new code
   • [ ] I am adding new logging messages
   • [ ] I am adding a new telemetry message
   • [ ] I am adding new credentials
   • [ ] I am adding a new dependency

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

   It adds a new overload for the function com.snowflake.snowpark.functions.round that allows to indicate the scale as an integer value. Also, it improves the code documentation for the other overloads of this function.

Pre-review checklist

(For Snowflake employees)

• [X] This change has passed precommit
• [ ] I have reviewed code coverage report for my PR in (Sonarqube)