Render black friday sale label.

[thijsoo]

Context

• We want to update de button text of the upgrade button for a sale.

Summary

This PR can be summarized in the following changelog entry:

• Updates the button label when the Black Friday sale is on.

Relevant technical choices:

Test instructions

Test instructions for the acceptance test before the PR gets merged

This PR can be acceptance tested by following these steps:

• Make sure the black friday sale is not running and you don't have premium enabled. Make sure that in the WP menu sidebar we render a upgrade button in our menu
• Make sure that in our topbar we also render a upgrade button.
• Enable the sale and make sure the label changes to 30% off - BF Sale like in the design.

Relevant test scenarios

• Changes should be tested with the browser console open
• Changes should be tested on different posts/pages/taxonomies/custom post types/custom taxonomies
• Changes should be tested on different editors (Default Block/Gutenberg/Classic/Elementor/other)
• Changes should be tested on different browsers
• Changes should be tested on multisite

Test instructions for QA when the code is in the RC

• QA should use the same steps as above.

QA can test this PR by following these steps:

Impact check

This PR affects the following parts of the plugin, which may require extra testing:

Other environments

• This PR also affects Shopify. I have added a changelog entry starting with [shopify-seo], added test instructions for Shopify and attached the Shopify label to this PR.

Documentation

• I have written documentation for this change. For example, comments in the Relevant technical choices, comments in the code, documentation on Confluence / shared Google Drive / Yoast developer portal, or other.

Quality assurance

• I have tested this code to the best of my abilities.
• During testing, I had activated all plugins that Yoast SEO provides integrations for.
• I have added unit tests to verify the code works as intended.
• If any part of the code is behind a feature flag, my test instructions also cover cases where the feature flag is switched off.
• I have written this PR in accordance with my team's definition of done.
• I have checked that the base branch is correctly set.

Innovation

• No innovation project is applicable for this PR.
• This PR falls under an innovation project. I have attached the innovation label.
• I have added my hours to the WBSO document.

Fixes #

[coveralls]

Pull Request Test Coverage Report for Build cc191e056becdfac168dd2a72d8d4fefd84a95f5

Details

• 0 of 9 (0.0%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 52.641%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
inc/class-wpseo-admin-bar-menu.php	0	4	0.0%
src/plans/user-interface/upgrade-sidebar-menu-integration.php	0	5	0.0%

Totals
Change from base Build 2acc881b6d4f4f8e2f33c0ee250b75fdc329d5d3:	0.0%
Covered Lines:	31039
Relevant Lines:	59388

---

💛 - Coveralls

[pls78]

CR && Acc: ✅