Add more information in the API Access page in Horizon (Access & Security)

When a user wants to connect an application or web portal to OpenStack API or EC2/S3 API, he needs to gather several information. For the moment, he have to download and open the appropriate openrc.sh or zip/ec2rc.sh file: this is great for CLI but painful for other apps that don't rely on env vars.

It would be more user friendly to display those information directly on the "API Access" page. In front of all the following field, the user would find an <input> with a value ready to copy :

# OpenStack

Username
Tenant name
Tenant ID
Authentication URL

# EC2 / S3

Access Key
Secret Key
Tenant ID
EC2 URL
S3 URL