Alan Agius 1da359ac08 feat(@angular-devkit/architect): add implementation for defaultConfiguration
With this change, the architect can be configured to use a default configuration when it's not provided as part of the target.

Consider the below, where `defaultConfiguration` is configured to `production`. Running `ng build` will be invoked with "production" configuration.

```js
"build": {
  "builder": "@angular-devkit/build-angular:browser",
  "defaultConfiguration": "production",
  "options": {
      ...
  },
  "configurations": {
    "production": {
        ...
    }
  }
}
```
2021-03-08 08:45:54 -06:00
..

Angular Build Facade

WIP