Add new availability message

[delputnam]

Changes proposed in this Pull Request

• Update the error message shown when attempting purchase a mapping for a subdomain that has a pre-existing conflicting CNAME record.

Testing instructions

• Apply D46527-code
• Create a CNAME record for a domain that you own (ex. foo.example.com)
• Attempt to purchase a mapping for the subdomain
• Make sure that the correct error message is shown:

[matticbot]

Test live: https://calypso.live/?branch=update/better-message-for-conflicting-subdomain

[matticbot]

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

App Entrypoints (~35 bytes added 📈 [gzipped])

name        parsed_size           gzip_size
entry-main        +52 B  (+0.0%)      +35 B  (+0.0%)

Common code that is always downloaded and parsed every time the app is loaded, no matter which route is used.

Sections (~81 bytes added 📈 [gzipped])

name     parsed_size           gzip_size
domains       +285 B  (+0.0%)      +81 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.

Async-loaded Components (~74 bytes added 📈 [gzipped])

name                             parsed_size           gzip_size
async-load-signup-steps-domains       +285 B  (+0.1%)      +74 B  (+0.1%)

React components that are loaded lazily, when a certain part of UI is displayed for the first time.

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.

[klimeryk]

Tested and works as expected. One small comment to fix before merging 🙇

[klimeryk]

Looks like this a component is a leftover from some delicious copypasta 😋

[delputnam]

Thanks! Fixed.

[a8ci18n]

This Pull Request is now available for translation here: https://translate.wordpress.com/deliverables/4144822

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

[a8ci18n]

Translation for this Pull Request has now been finished.