### Describe Your Changes
1) Changed table settings from a popup to a modal window to simplify
future functionality additions.
2) Added functionality to save selected columns when data is modified or
the page is reloaded. See #7016.
<details>
<summary>Example screenshots</summary>
<img alt="demo-1" width="600"
src="https://github.com/user-attachments/assets/a5d9a910-363c-4931-8b12-18ea8b3d97d8"/>
</details>
### Checklist
The following checks are **mandatory**:
- [x] My change adheres [VictoriaMetrics contributing
guidelines](https://docs.victoriametrics.com/contributing/).
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Co-authored-by: Roman Khavronenko <roman@victoriametrics.com>
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