[Cypress] Decide a naming convention for cypress snapshots

[GCHQ-Developer-530]

Summary

At the moment the cypress baseline snapshots are a mix of kebab case, camel case and just written out normally with white space in between words. I think it would make more sense for them all to match.

💬 Description

The image above shows the differences we have when naming the snapshots. We should decide how we want snapshots named and then go through and update snapshots to match that name style.

We'll have to update them in the compareSnapshot line in the Cypress files, and then delete the outdated screenshots with the old name style.

💰 Use value

It makes the code look more professional and less messy.

[MI6-255]

@MI6-286, could you consider this as part of the testing standards?

[MI6-255]

@ad9242 to add to this issue

[ad9242]

Agreed that this issue should encompass the work to ensure all components use the setThresholdBasedOnEnv() method described here: https://github.com/mi6/ic-ui-kit/issues/1755

[ad9242]

May want to also consider the focus indicator work covered here: https://github.com/mi6/ic-ui-kit/issues/1463 as that will also require the baseline images to be updated