Add support for sidecar containers

Deploy an application with a primary container as well as secondary sidecar containers. Something like:
``` C#
var builder = DistributedApplication.CreateBuilder(args);
builder.AddProject("webapplication")
.WithContainer("sidecar")
```
This should translate to

``` Bicep
containers: [
{
image: 'webpplication'
},
{
image: 'sidecar'
}
]
```