Add capability to 'gcp_storage_object' to enable folder object downloads and recursive capabilities

##### SUMMARY

As of right now gcp_storage_object isn't the most useful due to the lack of support regarding recursive and multi-file downloads. Instead we have to wrap gsutil rsync/cp commands with ansible shell execs.

##### ISSUE TYPE
- Feature Idea

##### COMPONENT NAME

gcp_storage_object

##### ADDITIONAL INFORMATION

The feature would be used to recursively download folders, files, or the entirety of the buckets contents.

I'm fairly indifferent on the syntax/usage, and mainly interested in having the capability.
```yaml
- name: Download bucket contents or folder recursively
gcp_storage_object:
bucket: bucket-name
action: download
src: "*" || src: "./" || src: "." || src: "foldername" || src: "foldername/*"
dest: "destfolder/"
state: present
```

Start with the gcp_storage_object entry point and its current download behavior. Define the supported recursive and multi-file source semantics and destination handling, then verify that folder, file, and whole-bucket downloads work.

Written by the indexing model from the issue text.