v3.5.2

• Updates minimum supported SDK version to Dart 3.0.
• Fixes all lint warnings.
• Added x-amz-security-token header support for session tokens.
• Wait for rename to finish before in fGetObject.
• Updated MinioError to implement the Exception interface.
• Added XML validation before parsing response body.
• Updated return type of presignedPostPolicy to Future<PostPolicyResult>.
• Replaced push with add for adding conditions to the policy.