Apply decorator once to a list of parameters

My main module takes a lot of secure parameters. Instead of having to do:
```
@secure()
param secretValueOne string
@secure()
param SecretValueTwo string
...
```

I want something like:
```
@secure(){
param secretValueOne string
param secretValueTwo string
...
}
```

It looks silly to repeat the secure decorator on each parameter when you have a large amount of parameters.

Start with the existing @secure() decorator and parameter declaration syntax described in the issue. Define how a grouped decorator should apply to every listed parameter, then verify that the proposed example parses and preserves secure behavior for each parameter.

Written by the indexing model from the issue text.