Allow setting root CA certificate for proxy

[flybd5]

Describe the request

Provide a way to add root certificates for authentication purposes.

If this is already possible, provide documentation of the procedure.

Describe the current behavior

There are some proxies (particularly in corporate networks) where the proxy hijacks the endpoint's SSL certificate and injects its own, which requires the IDE to be aware of the company's root CA certificate.

In 1.8 that can be done with keytool, but in 2.x there is no way to do this that I can see.

Arduino IDE version

2.0.3

Operating system

Windows

Operating system version

10

Additional context

Related

• Provide proxy settings auto-detection option #29
• https://forum.arduino.cc/t/adding-a-root-cert-to-the-ide-keystore/1085491

Issue checklist

• I searched for previous requests in the issue tracker
• I verified the feature was still missing when using the latest nightly build
• My request contains all necessary details

[ozantoteles]

The issue persists on newer versions (2.2.1) and on Linux and Appimage too. It would be great to provide a way to "ignore SSL" option at least.