Global settings improvements and protect against non-acknowledged changes

##### ISSUE TYPE
* Improvement Request

##### COMPONENT NAME
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UI
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##### CLOUDSTACK VERSION
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4.17.*.*
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##### SUMMARY
This request is for improvements for the "Global settings" screen.
1. As any user with correct privileges, Protect against "reset" button press without acknowledgement.
- On the "Global settings" screen there is no guard on the reset button.
- Clicking the reset button should prompt user. "Are you sure you want to reset "value" to "default value".
- Selecting the "Yes or Ok" button would update the value in the database with the default value.
- The "Cancel" button will close the prompt without changing any values.

2. As "Admin", the UI offers a way to update the default value stored in the database.

3. As "Admin", the UI offers an editable regular expression to test against, and enforce formatting for the value and default value.

4. As "Admin", the UI offers the ability to edit the description.

5. Any changes should be logged with before and after values.

6. As "Admin", the UI offers a way to update the "Category" field value.

從全域設定畫面開始，追蹤現有的重設動作和管理員控制項。檢視設定如何持久化以及變更如何記錄，然後將完成定義為受保護的重設，以及可編輯的預設值、驗證、描述、類別和變更前後的稽核項目。

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