vlib/io: fix reader bugs, make read_all take a config struct (#7361)

vlib/net/http/http.v

@@ -398,7 +398,7 @@ fn (req &Request) http_do(host string, method Method, path string) ?Response {
 	mut client := net.dial_tcp(host)?
 	// TODO this really needs to be exposed somehow
 	client.write(s.bytes())?
-	mut bytes := io.read_all(client)?
+	mut bytes := io.read_all(reader: client)?
 	client.close()
 	return parse_response(bytes.bytestr())
 }

vlib/net/smtp/smtp.v

@@ -95,7 +95,7 @@ pub fn (mut c Client) quit() ? {
 
 // expect_reply checks if the SMTP server replied with the expected reply code
 fn (c Client) expect_reply(expected ReplyCode) ? {
-	bytes := io.read_all(c.conn)?
+	bytes := io.read_all(reader: c.conn)?
 
 	str := bytes.bytestr().trim_space()
 	$if smtp_debug? {