Staging feed too difficult to use

@joperezr why is it 3 settings? Can we infer some of these? If stagingChannelEnabled isn't enough the channel should not show up if it won't work (the other 2 settings are set).

Before we stablize:

```
aspire config set -g features:stagingChannelEnabled true
aspire config set -g overrideStagingQuality Prerelease
aspire config set -g stagingPinToCliVersion true
```

After

```
aspire config set -g features:stagingChannelEnabled true
```