Plugins' platforms directory should not exist in tns_modules

Issue

Plugins' platforms directory should not exist in <project dir>/platforms/<platform>/.../app/tns_modules/ During project preparation CLI copies all node_modules to tns_modules directory and cleans their native files, located in their platforms directories. However, in case NativeScript plugin is a dependency of another NativeScript plugin and npm places it inside node_modules of the plugin, not at the root of the project, CLI does not clean the platforms directory of the inner plugin. This issues occurs mainly in case there's a local plugin.

Steps to reproduce:

1. Clone this repo:

$ git clone https://github.com/rosen-vladimirov/application-tns_modules-native-files.git

2. Get inside the nativescript-ui-listview directory and execute npm install there:

$ cd application-tns_modules-native-files/nativescript-ui-listview
$ npm i

3. Get back inside the project dir and build the application:

$ cd ..
$ tns build ios
$ tns build android

4. Check the following dir - it should not exist, but in fact it is there:

$ ls -l platforms/ios/applicationtnsmodulesnativefiles/app/tns_modules/nativescript-ui-listview/node_modules/nativescript-ui-core/platforms

$ ls -l platforms/android/app/src/main/assets/app/tns_modules/nativescript-ui-listview/node_modules/nativescript-ui-core/platforms

Full script:

git clone https://github.com/rosen-vladimirov/application-tns_modules-native-files.git
cd application-tns_modules-native-files/nativescript-ui-listview
npm i
cd ..
tns build ios
tns build android
ls -l platforms/ios/applicationtnsmodulesnativefiles/app/tns_modules/nativescript-ui-listview/node_modules/nativescript-ui-core/platforms
ls -l platforms/android/app/src/main/assets/app/tns_modules/nativescript-ui-listview/node_modules/nativescript-ui-core/platforms