Support functions for message in driver.wait()

[jackall3n]

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Supporting functions for message in driver.wait().

Description

This change allows users to pass a function that resolves an error message when the driver.wait() condition fails. Currently a string can be passed to the wait() method, now () => string can also be passed.

Motivation and Context

Currently a user only has the ability to pass a message containing information about the step at the beginning of the test. Giving a user the ability to pass a function that resolves a message allows the message to contain information that is made available at the end of the test. The motivation for this PR is to be able to write out information about the current state of the test results after a timeout period has expired.

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

• I have read the contributing document.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.