Add name property to installer-paths for type:drupal-library.

[greylabel]

Problem/Motivation:

Contrib often requires libraries to be installed to Drupal's docroot/libraries in a specifically named directories that can differer from the defaults provided by the libraries themselves. The webform module is an example. Although it provides drush commands and a drush make file, it does not out of the box provide a composer friendly solution.

Proposed resolution:

Add the name property to installer-paths for type:drupal-library in the template composer.json.

"docroot/libraries/{$name}": [
  "type:drupal-library"
],

This will allow specifying an arbitrary the directory name in docroot/libraries for libraries installed with composer. Example below.

"repositories": {
    ...
    "intl-tel-input": {
        "type": "package",
        "package": {
            "name": "jquery/intl-tel-input",
            "version": "v11.0.0",
            "type": "drupal-library",
            "extra": {
                "installer-name": "jquery.intl-tel-input"
            },
            "dist": {
                "url": "https://github.com/jackocnr/intl-tel-input/archive/v11.0.0.zip",
                "type": "zip"
            },
            "require": {
                "composer/installers": "~1.0"
            }
        }
    }
},
"require": {
    ...
    "jquery/intl-tel-input": "v11.0.0"
},