Improve dependencies logging

[belemaire]

This PR contains two commits

• c173c33 adds a new YarnLockParser utility class which as of now contains utility methods to parse and generate dependency trees out of a yarn.lock file.
  This utility class is used to replace primitive/limited dependency logging following Container generation. Complete dependency trees of all resolved native dependencies are now debug logged following Container generation along with the tree of potential mismatching native dependencies versions.

• 31982ff Leverage the new YarnLockParser class by adding a new command ern cauldron why, deprecating the ern why command that was too rudimentary and ultra slow to be of any practical use.
  This new command relies on the yarn.lock files stored in the Cauldron for each Container, and will list a dependency tree of any given native or JS dependency, which is a much faster way to check why a dependency is included in the Container of a native application version than having to go through Cauldron yarn.lock files manually following each dependency to walk up the tree.
  It will list each found version of the dependency as a dependency tree along with the resolved version of any dependency. For example :

➜ ern cauldron why react-native-code-push -d MyApp:android:1000.0.0

 └─ [email protected] [5.3.2]
    ├─ miniapp-one@https://github.com/foo/MiniAppOne.git#8cb271b3cd0492b622d392f5d0e28a106d5b42d0 [0.0.1]
    ├─ [email protected] [1.2.3]
    └─ miniapp-three@^4.0.0 [4.1.1]

➜ ern cauldron why react-native-electrode-bridge -d MyApp:ios:1000.0.0

 └─ [email protected] [1.5.17]
    └─ my-awesome-api@^0.2.1 [0.2.3]
       ├─ [email protected] [0.2.49]
       │   ├─ miniapp-one@https://github.com/foo/MiniAppOne.git#8cb271b3cd0492b622d392f5d0e28a106d5b42d0 [0.0.1]
       │   └─ [email protected] [1.2.3]
       └─[email protected] [0.2.1]