feat(contracts): implement 1-step undelegation for KGH (#353)

* feat(contracts): remove KGH share and modify KGH delegation func

* feat: review applied and restore stuffs related to undelegation

* feat: review applied

* feat(contracts): implement 1-step undelegation of KRO

* feat(contracts): add claim boost reward before delegation of KGH

* feat(contracts): implement 1-step undelegation of KGH

* feat(contracts): implement 1-step undelegation of KGH batch

* feat: review applied

* feat: review applied

* chore: update comment

* fix: remove duplicated arg for claim of boost reward

* feat: review applied

* feat: review applied

* feat(contracts): implement getKroAssets view func

* chore: remove duplicated index increment

* feat: transfer claimed boost reward when delegate KGH

* chore: update interface of undelegate func

* chore: restore condition check for transfer of claimed reward