High contrast cypress tests

[GCHQ-Developer-530]

Summary

At the moment, the following components have high contrast cypress tests:

• Page header
• Side navigation
• Search bar
• Stepper
• Status tag
• Switch
• Tabs
• Text field
• Toggle button group

💬 Description

The rest of the components need high contrast mode adding into the cypress tests.

Should be as simple as adding a new describe block with

before(() => {
    cy.enableForcedColors();
  });

  after(() => {
    cy.disableForcedColors();
  });

💰 Use value

Keeps all tests consistent and makes us more confident in our components in high contrast mode.

[MI6-255]

Make sure to test the focus state