refactor(schematics): foundation for cdk schematics (#13213)

* Moves the utility functions which will be needed for building CDK schematics to the CDK (`cdk/schematics`).
* Updates package tools to properly build schematics for CDK and Material (shared logic for building schematics; Material schematics depend on CDK schematics)
* Update to `ng-add`: The Angular CLI only installs `@angular/material` if someone runs `ng add @angular/material`. But since we need access to the utility functions from the CDK, we need to install the dependencies first, and then setup the project.

.github/CODEOWNERS

@@ -23,7 +23,7 @@
 /src/lib/progress-bar/**                           @jelbourn @crisbeto @josephperrott
 /src/lib/progress-spinner/**                       @jelbourn @crisbeto @josephperrott
 /src/lib/radio/**                                  @jelbourn @devversion
-/src/lib/schematics/**                             @amcdnl
+/src/lib/schematics/**                             @devversion @amcdnl
 /src/lib/select/**                                 @crisbeto
 /src/lib/sidenav/**                                @mmalerba
 /src/lib/slide-toggle/**                           @devversion
@@ -71,6 +71,7 @@
 /src/cdk/overlay/**                                @jelbourn @crisbeto
 /src/cdk/platform/**                               @jelbourn @devversion
 /src/cdk/portal/**                                 @jelbourn
+/src/cdk/schematics/**                             @devversion @jelbourn
 /src/cdk/scrolling/**                              @andrewseguin @crisbeto
 /src/cdk/stepper/**                                @mmalerba
 /src/cdk/table/**                                  @andrewseguin