[ic-button] - adds visual tests for hover & pressed states of buttons

[ad9242]

Summary

Investigate if it is possible to capture the hover & pressed states of buttons in the cypress visual regression tests

💰 Use value

Will catch when colors change & provide confidence in the component

Additional info

May be able to use something like the following: https://docs.cypress.io/api/commands/hover#Simulating-mouseover-event-to-get-popover-to-display

maybe "mousedown" for pressed state?

[MI6-286]

After a little investigation, it seems using cy.realMouseDown for the pressed state and cy.realHover for the hover state should give us what we need.