Fixing how test steps are extracted in case we need to go step by step

[akshar2401]

Pull Request Template

Description

Splitting by semicolon is not the right way to extract out the test steps from the whole expression as it could be present anywhere in comments, string literals, or interpolated strings. This pr utilizes PowerFx lexer to attempt to correctly compute the test steps in the formula. The logic is locale specific.

Checklist

• [X] The code change is covered by unit tests. I have added tests that prove my fix is effective or that my feature works
• [X] I have performed end-to-end test locally.
• [X] New and existing unit tests pass locally with my changes
• [X] I have commented my code, particularly in hard-to-understand areas
• [X] I have made corresponding changes to the documentation
• [X] My changes generate no new warnings
• [X] I used clear names for everything
• [X] I have performed a self-review of my own code

[github-actions[bot]]

Package	Line Rate	Branch Rate	Complexity	Health
Microsoft.PowerApps.TestEngine	91%	89%	838	✔
Summary	91% (2250 / 2470)	89% (514 / 578)	838	✔

Minimum allowed line rate is 85%