To add a components link to the sidebar refactoring was required to create unique URLs for themes and components. Before the query param was used. After changes, we have two URLs `/admin/customize/themes` and `/admin/customize/components`.
This commit adds an /admin/customize/theme-components route,
that opens the theme page with the components tab pre-selected,
so people can navigate to that directly.
As of #23867 this is now a real package, so updating the imports to
use the real package name, rather than relying on the alias. The
name change in the package name is because `I18n` is not a valid
name as NPM packages must be all lowercase.
This commit also introduces an eslint rule to prevent importing from
the old I18n path.
For themes/plugins, the old 'i18n' name remains functional.
provide the ability to edit theme settings in the json editor, and also copy them as a text file so they can be pasted into another instance.
Reference: /t/65023
A while ago we made a change to display a warning after installing a theme component when the admin tries to leave the page without adding the new installed component to any themes (see 5e29ae3ef5).
However there is an edge case that we forgot to address, and that's when an admin installs a component and then immediately opens the install modal again to install another one which can result in the warning being shown twice at the same time.
This PR prevents that by showing the warning when opening the install modal if the conditions are met (new component and not added to any themes) instead of showing it after installing the second component.
