Reset expired connections

[iamluc]

Summary

Ensure a connection is not used when its ConnMaxLifetime is exceeded

Currently, the ConnMaxLifetime is only checked in the release method. So a connection may be valid when added to the "idle" pool, but expired when "acquired".

In our application, the TCP socket is only alive for a few minutes, and I don't know why, but the isBad() method does not detect any issues.
But then when a query is sent to the ClickHouse server, we end up with broken pipe or EOF errors

[CLAassistant]

All committers have signed the CLA.

[jkaflik]

@iamluc, thanks for your submission. I will look and check if this is reproducible in a simple test.

BTW please sign CLA

[jkaflik]

I don't think it's something I can get easily reproducible in tests.
@iamluc, my opinion is it would be better to check lifetime inside isBad:

func (c *connect) isBad() bool {
	switch {
	case c.closed:
		return true
	}

	if time.Since(c.connectedAt) >= c.opt.ConnMaxLifetime {
		return true
	}

	if err := c.connCheck(); err != nil {
		return true
	}
	return false
}

[iamluc]

Thanks @jkaflik
PR updated with your suggestion and CLA signed!

Note: the changes in the import section are done automatically by the Golang plugin of VSCode. If it bothers you, I can revert this part

[jkaflik]

@iamluc thanks! imports change is fine. let me wait for green tests and we can merge it.