Asset group

[iboss-ptk]

This PR introduce concept of scope for limiter and upcoming rebalancing incentive

scope can be either denom or asset_group which can practically represent source chain or bridge. This is what changed in registering limiter:

{
  "register_limiter": {
-  "denom": "token1",
+  "scope": "denom::token1",
    "label": "1h",
    "limiter_params": {
      "change_limiter": {
        "window_config": {
          "window_size": "3600000000000",
          "division_count": "5"
        },
        "boundary_offset": "0.2"
      }
    }
  }
}

scope can be prefixed with either denom:: or asset_group:: to differentiate the scope variant.

In order to specify an asset_group as scope, it creating new group is requried

{ 
  "create_asset_group": {
    "label": "group0",
    "denom": ["denom0", "denom1"]
  }
}

it can also be removed, and the associated limiters will we removed along with it

{ "remove_asset_group": { "label": "group0" } }

mark_corrupted_assets & unmark_corrupted_assets also changed to mark_corrupted_scopes & unmark_corrupted_scopes

The assets that are within the corrupted scopes will be removed from the pool when the amount reaches 0 as before. The reference to the specific asset that is corrupted and reaches 0 will also be removed from asset_group. Once asset group emptied, it is also automatically removed.

[crnbarr93]

Few comments otherwise LGTM!

[iboss-ptk]

nice catches, will fix them!