refactor(FIR-46254): merge token and url caching

[ptiurin]

This pull request introduces a significant refactor of the token caching mechanism for authentication in the Firebolt Python SDK. The main changes involve replacing the previous filesystem-based token cache with a new, encrypted, file-based cache system, updating the Auth classes to use this new cache, and removing legacy token storage code. The update also ensures that account names are consistently set in authentication objects during connection setup.

Token caching and storage refactor:

• Introduced a new FileBasedCache class in src/firebolt/utils/cache.py that provides encrypted, persistent, file-based caching for authentication tokens and connection info, replacing the old TokenSecureStorage system. This includes logic for OS-specific cache directories, encryption, and expiry handling.
• Updated the Auth class in src/firebolt/client/auth/base.py to use the new _firebolt_cache for token retrieval and storage, including adding an account property to ensure tokens are cached per-account.
• Removed all references to the legacy TokenSecureStorage and related code from the authentication classes (UsernamePassword, ServiceAccount, ClientCredentials), and deleted the compatibility import in src/firebolt/common/token_storage.py.

Connection setup improvements:

• Ensured that the account_name is consistently assigned to the auth object in both async and sync connect functions, which is necessary for correct token caching and retrieval.

Data structure enhancements:

• Enhanced the ConnectionInfo dataclass to include a token field and a __post_init__ method for robust deserialization of nested dataclasses from cache.

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
98.3% Coverage on New Code
1.1% Duplication on New Code

See analysis details on SonarQube Cloud

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
98.3% Coverage on New Code
1.1% Duplication on New Code

See analysis details on SonarQube Cloud

[bogdantruta-firebolt]

I am guessing we also return the validity of the token? What is the tuple return needed for

[ptiurin]

yeah, token and its expiry - https://github.com/firebolt-db/firebolt-python-sdk/pull/454/files/88129aad4541917b102da74bf38f55ed6ff8f863#diff-ffbb4e973c25af4ceb5128e7cf8885e1c6c4df4949113a1e500bc8712f2ff525R140
Docstring needs to be updated.

[ptiurin]

Created merge_caching_bkp in case some merge conflicts were not resolved correctly.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
98.5% Coverage on New Code
1.0% Duplication on New Code

See analysis details on SonarQube Cloud