Introduce a "session timeout" counter in GUI

##### ISSUE TYPE

* Feature Idea

##### COMPONENT NAME

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UI
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##### CLOUDSTACK VERSION

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4.17.0.1
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##### CONFIGURATION

N/A

##### OS / ENVIRONMENT

N/A

##### SUMMARY

I would like to have a "counter" in the UI showing the time until the current session is closed and the user needs to authenticate again. In addition a button to "refresh" the session / restart the session time-out would be quite convenient.
For positioning i would suggest to place this in the top menue right beside the username and button for changeing the language-settings


##### STEPS TO REPRODUCE

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##### EXPECTED RESULTS

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##### ACTUAL RESULTS

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该 issue 将 CloudStack GUI 和顶部菜单确定为目标区域。首先跟踪 GUI 如何管理身份验证会话，以及用户名和语言控件如何进行渲染。完成的标准是 UI 显示剩余会话时间，并提供一种可正常工作的会话刷新方式。

由索引模型根据 Issue 内容生成。