to_char format change implemented

[sriram251-code]

closes #1186

This pull request improve functionality of to_char() method, adding new features to handle quivalent date time format convertion from snowflake.

Previous Behavior:
Snowflake code input: to_char(pos.createdwhen,'yyyymmdd') --output: 20241112
Databricks code output: TO_CHAR(pos.createdwhen, 'yyyymmdd') --output: 20240012

After the fix:
Databricks code output: TO_CHAR(pos.createdwhen, 'yyyyMMdd') --output: 20241112

[github-actions]

Coverage tests results

456 tests  +6   418 ✅ +2   5s ⏱️ -1s
  6 suites ±0    37 💤 +3 
  6 files   ±0     1 ❌ +1 

For more details on these failures, see this check.

Results for commit 377ea6d. ± Comparison against base commit 2b3d5f6.

♻️ This comment has been updated with latest results.

[jimidle]

Has this already been changed in the core version? Also, the tests are failing.

- functions/to_char.sql *** FAILED ***
  === Unexpected output (expected vs actual) ===
   SELECT                                       SELECT
  !  TO_CHAR(CURRENT_TIMESTAMP(), 'yyyyMMdd')     TO_CHAR(CURRENT_TIMESTAMP(), 'yyyymmdd'); (AcceptanceSpec.scala:15)