Describe the bug
schemachange ignores session_parameters defined in connections.toml.
In SnowflakeSession.py, schemachange constructs its own session_parameters = {"QUERY_TAG": ...} and passes that into snowflake.connector.connect(...), which overwrites any session_parameters from the TOML connection (e.g., QUOTED_IDENTIFIERS_IGNORE_CASE=false).
As a result, users cannot control session-level behavior via connections.toml.

To Reproduce

1. Create a connections.toml with a named connection (matching --connection-name) that includes session_parameters:

   [STG]
   account = "xxx"
   user = "xxx"
   authenticator = "externalbrowser"
   role = "STG_ROLE"
   warehouse = "STG_WH"
   database = "DB_STG"
   schema = "ADM"
   
   session_parameters = { QUOTED_IDENTIFIERS_IGNORE_CASE = false }

2. Run schemachange using that connection:

   schemachange --connections-file-path ./connections.toml --connection-name STG      --config-folder ./_INFRA/configs --config-file-name schemachange-config.yml

3. During the same run (e.g., via a small script or interactive session), check the parameter:

   SHOW PARAMETERS LIKE 'QUOTED_IDENTIFIERS_IGNORE_CASE' IN SESSION;

   Actual: value remains TRUE (or the user/account default), not false from TOML.

Expected behavior
schemachange should respect session_parameters provided via connections.toml.
If schemachange needs to set QUERY_TAG, it should merge its tag into user-supplied session_parameters rather than overwrite them. Alternatively, avoid passing session_parameters to connect(...) and set QUERY_TAG post-connect via ALTER SESSION.

Screenshots

Schemachange (please complete the following information):

• Version (e.g., 3.5.3): 4.0.1

Additional context

• Root cause: SnowflakeSession builds self.session_parameters = {"QUERY_TAG": ...} and passes it to snowflake.connector.connect(...), eclipsing TOML-defined session_parameters.

• Proposed fixes:

  1. Merge TOML session_parameters with schemachange’s QUERY_TAG before connecting.
  2. Do not pass session_parameters at connect time; keep using ALTER SESSION SET QUERY_TAG so the connector can apply TOML session parameters as intended.