Support HTTPS network serving

[DD3Boh]

Implement HTTPS support for network serving, with self signed certificates that can be imported and exported. This feature has been talked about in issue #16887 and #16912 before submitting the PR.

The implementation allows accessing the network serving on the fixed 6806 port in both HTTP and HTTPS mode, filtering according to the first bytes of the input that the server receives.

[DD3Boh]

This time around the fixed port supports both http and https. I didn't implement the same thing for the dynamic port, since I think this is a more complicated handling compared to straight http or https (since it leverages cmux and filtering). For that reason, I only wanted to add it where I think it's actually needed and useful, which is the fixed port.
But let me know if you think it should also go on the dynamic port.

[88250]

Okay, we will only implement HTTPS on port 6806; dynamic port support will not be implemented for now. Thank you.

[88250]

感谢你的贡献，思源有你更精彩！
Thank you for your contribution. SiYuan will be more wonderful with you!

[88250]

Several adjustments were made:

• Fine-tuned language text: Implement HTTPS network serving #16912 (comment)
• Added missing multilingual configuration files: Implement HTTPS network serving #16912 (comment)
• The "Open in browser" button still uses HTTP: Implement HTTPS network serving #16912 (comment)

[TCOTC]

“启用 HTTPS”、“导出 CA 证书”、“导出 CA 证书包”、“导入 CA 证书包”应该是“网络伺服”的子项，在开启“网络伺服”之后才显示

[88250]

@Vanessa219

[TCOTC]

@Vanessa219 关闭网络伺服的时候会隐藏下面的子项，但重启之后子项又直接显示出来了：