SNOW-3995071: Expand tilde in token_file_path

[cristiangirlea]

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

   Fixes SNOW-3995071: PAT to support path expansion #3006

2. Fill out the following pre-review checklist:

   • 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 modifying authorization mechanisms
   • I am adding new credentials
   • I am modifying OCSP code
   • I am adding a new dependency

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

   token_file_path was passed straight to open(), so a path using the home shorthand, such as ~/.snowflake/pat.token in connections.toml, failed with FileNotFoundError. This PR reuses the existing util_text.expand_tilde helper, which SNOW-3020359 expand tilde to key file path in connection #2759 introduced for private_key_file, so both connection parameters behave the same way. Non-string values and environments where the home directory can't be resolved pass through unchanged, as with private_key_file.

   The async SnowflakeConnection inherits the same __config path, so it is covered too.

   Test: test_pat_token_file_path_expands_tilde points HOME/USERPROFILE at a temp directory, connects with PROGRAMMATIC_ACCESS_TOKEN and token_file_path="~/.snowflake/pat.token", and asserts that the token read from the file is the one sent in the login request. Without the fix it fails with the error reported in the issue: FileNotFoundError: [Errno 2] No such file or directory: '~/.snowflake/pat.token'.

   Also ran test_connection.py, test_auth_keypair.py, test_text_util.py and aio/test_connection_async_unit.py locally (152 passed), and pre-commit passes on the changed files.

[cristiangirlea]

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