Publish button should reflect publish status

Designs

The current and proposed sidebar header actions are shown below:

Current Designs	Updated Designs

This story relates to the publish button. Edit/Open component changes to be addressed in issue 1795.

Publish Button State Designs	Description
	Published: Block is published and there are no edits made since previous publish
	New: Block has never been published
	Edited: Block has been published before but there are draft changes that have not yet been published

Spec

1. Published stroke color: stroke color: #5690BB; Fill: #F1F6FA.
2. New stroke color: #F4B57B; Fill: #FCF4EA.
3. Edited stroke color: F4B57B; Fill: #FCF4EA.
4. Width of publish button should be set to fill container. (changes to open/ edit button are out of scope, but noting here that the open/edit button width should hug contents).

In scope

1. Changes to publish button design: color, stroke with left side thicker stroke
2. Changes to publish button text to reflect status: Published, Publish New, Publish Changes

Not in scope

1. Overflow menu behavior
2. Edit/ Open button changes

Related Tickets

Sidebar "Edit" button visual enhancement #1795
Publish section/subsection #1977

Start by locating the sidebar header publish button and the code that determines whether its block is published, new, or edited. Implement the three specified labels and visual states, make the button fill its container, and keep overflow-menu and Edit/Open changes out of scope.