Allowing passing additional context to the html function in spa mode

### Prerequisites

- [X] I have written a descriptive issue title
- [X] I have searched existing issues to ensure the feature has not already been requested

### 🚀 Feature Proposal

Currently SPA mode doesn't allows to pass additional context to the render function.

### Motivation

I have a case that I wan't to render some stuff on the **html** not related to the React app.

For example, render app version inside a **meta** tag.

### Example

```js
reply.html({
version: env.BUILD_VERSION
});
```