Request to improve updateNetwork api

##### ISSUE TYPE

* Improvement Request / Future request

##### COMPONENT NAME

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API
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##### CLOUDSTACK VERSION

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4.18.1.0
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##### CONFIGURATION

N/A
##### OS / ENVIRONMENT

N/A

##### SUMMARY

Request to improve updateNetwork api to add/change ipv6 CIRD, ipv6 gate, ipv6 end ,start ip, router ipv6.

##### STEPS TO REPRODUCE

Create ipv4 only guest network. Try to add ipv6 CIDR, gateway, start ip, end ip.

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##### EXPECTED RESULTS

Possibility to change the settings described above using the interface or api
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##### ACTUAL RESULTS

You won't be able to do this either through the interface or the api

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從 updateNetwork API 入口點開始，針對 IPv4-only 客戶端網路重現該請求。確定透過 API 和介面變更 IPv6 CIDR、閘道、起始和結束 IP 以及路由器 IPv6 時的預期行為。當能夠透過所要求的路徑成功變更這些設定時，即表示完成。

由索引模型根據 Issue 內容生成。