Add "analyticsLabel" as a config option for CTAs

[rosiegrant]

Our analytics events optionally accept a ctaLabel attribute. Right now, the only way for an admin to configure this is by entirely overwriting eventOptions, but to do so, they need to add in a lot of logic (whether it's on vertical / universal, the entity Id, etc).

We should expose this label attribute as a top level config option so it's easier to use it.

• Defaults to null
• Should accept either a string, or a function that takes in the result data.
• If present, should be passed as ctaLabel attribute as a part of eventOptions, like this:
  

Here's what callsToAction would look like:

const callsToAction = [{
  // Label below the CTA icon, default null
  label: 'cta label',
  // Icon name for the CTA that is one of the built-in icons, defaults to undefined (no icon). If your icon
  // is not recognized it will default to 'star'.
  icon: 'star',
  // URL to a custom icon for the cta. This takes priority over icon if both are present, default is
  // no icon url.
  iconUrl: 'https://urltomyicon.com/customicon.gif',
  // Click through url for the icon and label
  // Note, a protocol like https:// is required here.
  url: 'https://yext.com',
  // Analytics event that should fire, defaults to 'CTA_CLICK':
  //       'TITLE_CLICK',
  //       'CTA_CLICK',
  //       'TAP_TO_CALL',
  //       'ORDER_NOW',
  //       'ADD_TO_CART',
  //       'APPLY_NOW',
  //       'DRIVING_DIRECTIONS',
  //       'VIEW_WEBSITE',
  //       'EMAIL',
  //       'BOOK_APPOINTMENT',
  //       'RSVP'
  analytics: 'CTA_CLICK',
  //NEW, passed as a ctaLabel for the event.
  analyticsLabel: 'My CTA Label',
  // The target attribute for the CTA link, defaults to '_blank'. To open in a new window use '_blank'
  target: '_blank',
  // The eventOptions needed for the event to fire. Either a valid json string, an object, or a function that
  // takes in the result data response.
  // By default, if no event options are specified the SDK will try to add verticalKey, entityId, and searcher options
  // to the analytics event.
  eventOptions: result => {
    return {
      // The vertical key for the CTA. If unspecified, this defaults to the vertical key this cta is a part of
      verticalKey: "people",
      // The entity id of the result this cta is a part of, defaults to the entityId field in Knowledge Graph
      entityId: result.id,
      // If the CTA is inside a vertical search, defaults to the value "VERTICAL",
      // if is inside a universal search, defaults to the value "UNIVERSAL"
      searcher: "VERTICAL",
      //ADDED - passed as a ctaLabel for the event.
      ctaLabel: "My label",
    };
  }
}]