feat(stack): introduce stack list command

Description

This change set implements a new glab stack list command to easily display all the entries of the current stack.

🔈 Please do review commit-by-commit.

Refs #7613 (closed)

How has this been tested?

• Create a new stack
• Save some diffs
• Run glab stack list

Screenshots (if appropriate):

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)
• Documentation
• Chore (Related to CI or Packaging to platforms)
• Test gap