Packages: Remove unused domain utils package

[tyxla]

Proposed Changes

While working on #74399 I realized that the getDomainSearch() selector is the only instance where the @automattic/domain-utils package is used, but that selector was unused, too (since #75269).

So, this PR removes that selector, and the @automattic/domain-utils package altogether.

Testing Instructions

Verify the removed selector and package are not in use.

[github-actions]

Calypso Live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:commit-8bc6ea62a151ddb01ac7142da008e0e2528f5ed4

Jetpack Cloud live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:commit-8bc6ea62a151ddb01ac7142da008e0e2528f5ed4&env=jetpack

[matticbot]

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

App Entrypoints (~99 bytes removed 📉 [gzipped])

name           parsed_size           gzip_size
entry-stepper       -186 B  (-0.0%)      -99 B  (-0.0%)

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

Sections (~100 bytes removed 📉 [gzipped])

name             parsed_size           gzip_size
sites-dashboard       -186 B  (-0.0%)     -100 B  (-0.1%)
settings              -186 B  (-0.0%)     -100 B  (-0.0%)
hosting               -186 B  (-0.0%)     -100 B  (-0.0%)
home                  -186 B  (-0.0%)     -100 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 (~100 bytes removed 📉 [gzipped])

name               parsed_size           gzip_size
async-load-design       -186 B  (-0.0%)     -100 B  (-0.0%)

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.

[noahtallen]

Verified it doesn't appear elsewhere 👍