No warnings for invalid syntax submissions

I noticed that invalid syntax gets silently submitted without any warnings.

Would be great to get notified about these syntax issues in submitted goggles.

This way, authors could fix them in their source files.

So, the goggle source code displayed on the brave search about page would equal the hosted code.

Here are some of the issues which don't result in warnings:

## Invalid Value

### Options
```
$discard=4,site=msn.com
```

https://github.com/Killthenews/brave/blob/de522bcc456646547f815a3de9ad4fcfa3494f35/news#L11-L18

### Metadata
```
! public: foo
```

- Expected behavior: Failing submission
- Actual behavior: Gets submitted as private goggle

## Illegal Range Value

Same for out of scope values for the action options:

```
$boost=30,site=github.com
```

https://github.com/9ktz/googles-technical/blob/cb75f9a9e4a9ce2f1d0a3304dbfddc57674fb96d/github.google#L8-L10

## Multiple `$`'s

Same for having multiple `$` inside the options part of the instructions.

```
bill_id=201720180SB1121$inurl,$boost=8
```

https://github.com/clening/DataProtectionGoggle/blob/19a3f9fd4bc9543c8f45ebfe4d0780826dc0ac18/dataprotection.goggle#L85

Start by tracing how Goggles submissions validate syntax, using the invalid examples in news, github.google, and dataprotection.goggle as cases. Check how invalid values, out-of-range action options, and multiple `$` characters are handled; done means these submissions produce warnings or fail instead of being silently accepted, and hosted source matches the submitted code.

Written by the indexing model from the issue text.