Improve the code quality of on_demand_feature_view.py and its related transform functions. #4202

Expected Behavior

The code quality should be high for Feast.

Current Behavior

The SonarCloud service shows there are several improvements need to be done.

Steps to reproduce

Analyze the code by SonarCloudservice (free for open source project).

Specifications

• Version: 0.37.1
• Platform:
• Subsystem:

Possible Solution

Improve the code quality by following the suggestions from SonarCloud