composite-checkout: Clarify label for full credit payment method

[nbloomf]

Changes proposed in this Pull Request

• Change the label on the full credits payment method from "WordPress.com Credits: X" to "WordPress.com Credits: X available", to help clarify what that number means.

At the moment it's easy to misunderstand the full credits payment method as changing the product price or using all credits on the account.

Testing instructions

Enter checkout with enough credits to cover the purchase (to trigger the full credits payment method) and inspect the label:

[matticbot]

Test live: https://calypso.live/?branch=update/full-credits-label-in-composite-checkout

[matticbot]

Here is how your PR affects size of JS and CSS bundles shipped to the user's browser:

Sections (~36 bytes added 📈 [gzipped])

name      parsed_size           gzip_size
checkout        +69 B  (+0.0%)      +36 B  (+0.0%)

Sections contain code specific for a given set of routes. Is downloaded and parsed only when a particular route is navigated to.

Legend

What is parsed and gzip size?

Parsed Size: Uncompressed size of the JS and CSS files. This much code needs to be parsed and stored in memory.
Gzip Size: Compressed size of the JS and CSS files. This much data needs to be downloaded over network.

Generated by performance advisor bot at iscalypsofastyet.com.

[a8ci18n]

⚠️ This change will be queued for retranslation. We'll display the English text until then.

[sirbrillig]

❤️ I love it.

[a8ci18n]

This Pull Request is now available for translation here: https://translate.wordpress.com/deliverables/3784269

Thank you @nbloomf for including a screenshot in the description! This is really helpful for our translators.

[a8ci18n]

Translation for this Pull Request has now been finished.