Add new test cases for upgrades code - to increase code coverage

[ann-sherin]

• Review coverage report generated from pytest for upgrades, and add tests based on that.
• Test case covering these cases:

• define line in different ways, like linecode, geometry, direct definition
• define transformer in different ways, like xfmr code

Coverage report is generated using this:
pytest --cov --cov-report=html tests
)