Test: check content of currently open slide

[anon-pradip]

Description

This PR checks the content of the slide which appears when a user opens .md file in presentation viewer using the scenario:
Scenario: check content of a slide

Whenever an user opens the md file in presentation viewer, locator currentSlideSelector selects the first slide (current open slide). We then get that slide's content using getCurrentSlideContent and finally assert that content with the expected one using await expect(getCurrentSlideContent).toBe(content)

Related Issue

• Part of [Test] Add UI testing #16

Motivation and Context

How Has This Been Tested?

• test environment:
  Locally and CI

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)
• Tests only (no source changes)
• Documentation only (no source changes)
• Maintenance (e.g. dependency updates or tooling)

Checklist:

• Code changes
• Unit tests added
• Acceptance tests added
• Documentation updated