Support non-object types

[stelcheck]

Topic instances should be allowed to be:

• Numbers
• Booleans
• String

... and so on.

Suggestion:

export default class extends ValidatedTopic {
  /**
   * Topic configuration
   */
  public static index = ['userId']
  public static indexType = Index
  public static vaults = {
    someVault: {}
  }
  
  /**
   * TODO: how do we specify validation?
   */
  public static type = number
}
```/