set templateContext (templateDataParameters) {
    this._templateDataParameters = templateDataParameters
  }
This templateDataParameters object can be accessed from the dialog text templates.
E.g. a templateDataParameters object of: `{ name: 'Mary' }` can then be used in the following
dialog text:
  `Hello, <%=o.name%>`
Which then appears as:
  `Hello, Mary`

@param {Object} templateDataParameters - used for interpolation.