Added linting rule exceptions for 'test/utils/test_file.py' in 'pyproject.toml'. Specifically, the 'W291' error which checks for trailing whitespace is ignored for this test file. This is necessary to test whether 'read_txt_file' function in 'test_utils.py' correctly ignores trailing whitespaces in varies test scenarios.
Refactored import paths for test utility methods across multiple test files to align with a recent package restructure. Enriched 'read_txt_file' functionality in 'file.py' allowing to optionally skip empty lines, enhancing flexibility for various use-cases. Added tests for the new 'read_txt_file' behavior in a new 'test_file.py'. Renamed 'utils.py' in test package to 'test_utils.py' for better differentiation from the util package in the source code.