Make the webpack dependencies prod dependencies of this plugin

[sis0k0]

Issue Checklist

• You are submitting: a feature request

Current behaviour

Currently, when installing the nativescript-dev-webpack plugin, some development dependencies are added to the package.json of the project. These dependencies are needed for the webpack build.

Problems

1. It's hard to upgrade to newer {N}-dev-webpack versions that require different dependencies. You have to manually invoke ./node_modules/.bin/update-ns-webpack --deps. This is a very annoying thing to do for all {N} apps and plugins in the {N} organisation.
2. The dependencies list in the project's package.json gets huge and it's often hard to recognize which are the webpack dependencies.
3. For Angular projects one of the added dependencies is @ngtools/webpack. However, the @angular-devkit/build-angular package has a dependency to @ngtools/webpack. That means that if your project has a dependency to @angular-devkit/build-angular (as the default NG web projects do), this can lead to multiple versions of the @ngtools/webpack plugin in your project. Having multiple versions of that plugin causes the webpack compilation to fail - https://github.com/angular/angular-cli/blob/master/packages/ngtools/webpack/src/loader.ts#L36-L43.

Proposed solution

Solution for 1. and 2. - all dependencies that are currently added to the project's package.json, will be dependencies of the nativescript-dev-webpack plugin. They won't be added to the project's package.json anymore.
Solution for 3. - all {N} Angular projects and templates should have a dependency to @angular-devkit/build-angular. That way, the {N}-dev-webpack plugin won't have to have a dependency to @ngtools/webpack, because the above is already brought to the project by @angular-devkit/build-angular.

Tasks breakdown

1. Make all packages from the dependencyManager dependencies of the nativescript-dev-webpack plugin.
2. Make the update-ns-webpack script remove all unneeded dependencies from the project.
3. Make the update-ns-webpack script update or add if missing the @angular-devkit/build-angular and @angular/compiler-cli dependencies.
4. Update all {N} apps in the {N} organization by removing their webpack dependencies.
5. Add @angular-devkit/build-angular as dependency to all apps and templates in the {N} organization.
6. Update @nativescript/schematics - remove the adding of webpack dependencies there.

[sis0k0]

Released with 0.14.0.