[PT Run] Find applications using the PATH env variable

[alekhyareddy28]

Summary of the Pull Request

• To index applications which are pointed to by the PATH environment variable.

PR Checklist

• Applies to [Tracker, PT Run] Find applications inside environment path #4200
• CLA signed. If not, go over here and sign the CLA
• Tests added/passed
• Requires documentation to be updated
• I've discussed this with core contributors already. If not checked, I'm ready to accept this work might be rejected in favor of a different grand plan. Issue number where discussion took place: #xxx

Detailed Description of the Pull Request / Additional comments

These are the changes made in this PR -

• All the locations which are pointed to by the PATH environment variable would be indexed for applications.
• To emulate the working of the start menu, these run commands will not show up unless the query matches the name.

eg:
Terminal -

Winver -

Validation Steps Performed

• Added unit tests.
• All existing unit tests pass.
• Manually validated the working.

[dsrivastavv]

LGTM!