Description

Implement several functions to work with Issue Links.

Motivation and Context

This continues the work of @replicaJunction on branch PSJira/feature-issue-links
This implements (in part) #36

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:

• My code follows the code style of this project.
• [ x I have added Pester Tests that describe what my changes should do.
• I have updated the documentation accordingly.