Make grammar data loadable as an RL module and usable in JS

Make grammar data loadable as an RL module and usable in JS

* Load the data of this variable from a JSON file to the same
  data structure that ResourceLoader uses for digitTransformTable,
  pluralRules, etc.
* Change the JSON structure to ensure the order of the rules.
  Otherwise JavaScript processes the keys in a random order.
* Delete the grammar code from JS and replace it with
  the same logic that is used in PHP for processing the data.

For now this is done only for Russian.

The next step will be to make the PHP and JS
data processing logic reusable.

Bug: T115217
Change-Id: I6b9b29b7017f958d62611671be017f97cee73415