Authentication provider: `Simulator` -> Customize token claims in config

When running in development mode, there should be an option to tell DAB to automatically assume that the request is authenticated and consider any role passed in via X-MS-API-ROLE valid, to facilitate debugging and testing of defined permissions. For example, this could be a configuration that defines what I just described:

```json
"runtime": {
"host": {
"mode": "development",
"authentication": {
"provider": "emulator",
}
}
}
```

The `emulator` provide could also, in future, allow for more configuration so that also claims could be injected in the context that is available to the developer, in order to also more easily debug policies.

For example:

```json
"runtime": {
"host": {
"mode": "development",
"authentication": {
"provider": {
"name": "emulator",
"settings": {
"claims": {
"email":"john.doe@contoso.com"
}
}
}
}
}
}
```