Add an indicator to display whether a product has been changed since last published

[spencern]

Using the hash created in #4264 add an indicator to the PDP to inform the user of unpublished changes to a product. The indicator should show if the product or any of it's variants or options has unpublished changes.

Edit By @mikemurray

Historically we've used "dots" with edit icons to indicate changes

The home for these "indicators", whatever form they take, should be placed in the toolbar either next to the publish button or take the form of the publish button.

[kieckhafer]

Documentation on what was done in #4264:

## `hashProduct(product, collections)`

The purpose of this function is to create a hash of a product, for comparison purposes to see if any changes have been made.

After the removal of revisions, we no longer have a way to determine if a product has changed since the last time it was viewed. This hash will allow the end-user to hash their current product, and compare hashes with the Catalog product.


`hashProduct(product, collections)`
- @param {Object} product - A product object
- @param {Object} collections - Raw mongo collections (Products is required)

Inside the function, there is a `const` called `skippedFields`, which takes an array of field names (strings), and skips these fields when hashing. We do this to skip fields such as the `hash` itself, and `createdAt` and `updatedAt`, which will always change, and are not user created.

The function returns the original product object, with the hash either updated or added to the object.

[rymorgan]

Currently, I'm getting this tooltip showing up no matter if I have published changes or not. As part of this, the tooltip should not be there when there and no changes to be published. Additionally, the publish button should show as disabled.

[rymorgan]

When there are changes that need to be published we use a small overlapping indicator dot to emphasize that changes need to be published. We also enable the button. I'm using the new button component here and style guide rules that only use the outline button for a secondary button. So in this instance, it would be a solid button with blue for emphasis.

When there are no changes to be published the button is in a disabled state.

*Note, it would be good have a simple animation where the indicator shrinks/animates out of view when you hit publish.