Simplify self-signed certificates usage with HTTPS

[slvrtrn]

Initially reported in #164

We have a few options:

• Add an example based on Add example in how to use this with a https clickhouse URL #134 (comment)
• Add an example on adding the cert into the OS trust store, see the first part of Cannot use custom CA or ignore self-sign verification #164 (comment)
• Add a feature in the client, see the second part of Cannot use custom CA or ignore self-sign verification #164 (comment) + Cannot use custom CA or ignore self-sign verification #164 (comment)