Add layer support

Support up to 4 layers ARN.
Downside : updating the function code when layer are associated, even not changing the code, will create a new function version (code + layer <> code). Adding the layers will create another version also. So using layers will (always) lead to create new versions.

Managing non-existent version/alias

The Code Deploy application and deployment group needs to exist but a first version and alias are not mandatory anymore, the action will create a numeric version and the alias if non-existent.

First version

v1

Add debug