cacheActionOnLanks (actionName) {
    for (const cachedLank of Object.values(this.lankCache)) {
      if ([...Object.keys(cachedLank.thangType.getActions())].indexOf(actionName) !== -1) {
        cachedLank.queueAction(actionName)
      }
    }
  }
Adds an action to preload on the lank.
This will rasterize the action in the preload cinematic step thus avoiding
gray blobs during the cinematic.

We currently preload the used actions on all lanks.

@param {string} actionName - name of the action to queue on the lank.