…in compilation

With this change we align the copying of assets between `ng build` and `ng serve`. Previously in `ng serve` already copied assets where not overridden.

More info: https://webpack.js.org/plugins/copy-webpack-plugin/#force

Closes #18787

(cherry picked from commit 4d2f4ec)

When using the non-deprecated localization options, the development server was not properly setting the HTML `lang` attribute for the application.  This change ensures that the active locale is used within the application's index HTML file.

Closes #18094

(cherry picked from commit 58a7dea)

The error message for when a TypeScript or JavaScript file is incorrectly used as a style or template within a component will now also provide the name of the file being incorrectly used.

(cherry picked from commit 4887f59)

…fferential loading

Previously, the cached integrity values for a subsequent differential loading build would not be properly integrated.  This resulted in builds with incorrect integrity values after an initial build.  The cached differential loading builds will now use the correct integrity values on subsequent builds.

Closes #18254

(cherry picked from commit eac9e99)

…ntext

This commits adds a base href value in the karma context iframe used to run unit tests where a unit test throws:
No base href set. Please provide a value for the APP_BASE_HREF token or add a base element to the document.
Even if the application is fine.
This is because the index.html from Angular CLI contains a base href value, but not the Karma context iframe.
So when adding a unit test with a testing module that imports a NgModule, for example AppModule,
which itself imports RouterModule, the unit test used to throw an error (regression appeared in router 3.1).
That could be solved by either adding `RouterTestingModule` to the testing module,
or by adding a provider `{ provide: APP_BASE_HREF, useValue: '/' }`, but required to understand the issue.
This solves the issue in a transparent way: developers won't even encounter the problem anymore.

Closes #19116

(cherry picked from commit ae94245)

…ion 3.1.2

Closes: #19134
(cherry picked from commit 46ef4cf)

This option is used to mark deprecated options as such in AIO.

(cherry picked from commit a09a2e4)

(cherry picked from commit 9768230)

`=true` us redundant

(cherry picked from commit 5f930c9)

…sal test

This reverts commit ad60c2f.

CI failed and were unable to release. Trying again with recent fixes.

This reverts commit 1ab5998.

Another release attempt after CI fixes.