prevent parentheses in filenames being stripped out

[davidjgoss]

Description

Prevent parentheses in filenames from being incorrectly stripped out when parsing the raw stack frame.

This is done by changing extractLocation, which previously removed all parens from its input, and now just strips them from the start and end (including multiple, which can happen with nested evals) which I think was probably the original intent.

Motivation and Context

Fixes #62.

How Has This Been Tested?

Added a test with an example stack (thanks to @mattwynne work in #61)

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• npm run lint passes without errors
• npm run test passes without errors
• I have read the contribution guidelines
• I have updated the documentation accordingly
• I have added tests to cover my changes