feat: added options for static-ip & custom root CA

[normanre]

Hello everyone,

I added these two options to configure a http.Client for the cli:

1. static-ip: With this option a static ip is used and DNS resolution is skipped but still the host of endpoint is used
2. root-ca: With this option someone can define a custom root ca

I did this because DNS and certificates resolution does not work as expected on Termux for Android. With these two additions this cli can be used for Android.

One quirk with Termux is that export HCLOUD_CONFIG="$HOME/.config/hcloud/cli.toml" has to be set (for example in .bashrc)

I hope this helps also someone else.

[phm07]

hcloud already allows configuring the API endpoint using the endpoint option. Why would it be necessary do add another option?
Also, would it not be possible to install the root CA locally?

[jooola]

You might also be able to leverage SSL_CERT_DIR or SSL_CERT_FILE to set custom root CAs.

See https://pkg.go.dev/crypto/x509#SystemCertPool