Complete metadata implementation

[failfmi]

Remove the hard-coded metadata used from node-template and add the missing metadata types. Keep in mind that metadata type path has to be used if you want to successfully connect to polkadotjs, as it is uses path field to rebuilt most types and those paths have to be consistent with Substrate.

Example:

  /**
   * Lookup8: frame_support::dispatch::PerDispatchClass<sp_weights::weight_v2::Weight>
   **/
  FrameSupportDispatchPerDispatchClassWeight: {
    normal: 'SpWeightsWeightV2Weight',
    operational: 'SpWeightsWeightV2Weight',
    mandatory: 'SpWeightsWeightV2Weight'
  },
  /**
   * Lookup9: sp_weights::weight_v2::Weight
   **/
  SpWeightsWeightV2Weight: {
    refTime: 'Compact<u64>',
    proofSize: 'Compact<u64>'
  },