Feature rquest: enable deploying lambda with container image

Hi there,

### Feature
It would be nice to have support for using a container image as the deployment package of Lambda.

### Use case
Sometimes we use heavy libraries in our Lambda that the 250MB size limit of a .zip package simply does not suffice. Therefore, a container image that can go up to 10GB would help.

### Current workaround
Now, we are manually modifying *package_transfrom.sh* and add *--image-repository* argument to *sam package*

Start by inspecting package_transfrom.sh and the existing sam package invocation to understand how deployment packages are selected. Determine the changes needed for container-image deployment, then verify that the framework can deploy a Lambda using an image repository instead of only a .zip package.

Written by the indexing model from the issue text.