Added options to retain info and state mqtt messages

[jeroenst]

Description:

With this pr it is possible to retain info and state messages, configurable with inforetain and stateretain commands in the console.

#11067

Checklist:

• The pull request is done against the latest development branch
• Only relevant files were touched
• Only one feature/fix was added per PR and the code change compiles without warnings
• The code change is tested and works on Tasmota core ESP8266 V.2.7.4.9
• The code change is tested and works on Tasmota core ESP32 V.1.0.5-rc6
• I accept the CLA.

NOTE: The code change must pass CI tests. Your PR cannot be merged unless tests pass

[s-hadinger]

Make sure to honor SetOption 104 no_retain and never send a retained message if it's set. Otherwise it will close the Mqtt connection

[jeroenst]

Make sure to honor SetOption 104 no_retain and never send a retained message if it's set. Otherwise it will close the Mqtt connection

This is honoration is already in the current code:

Tasmota/tasmota/xdrv_02_mqtt.ino

Lines 326 to 328 in 73e2e4f

	if (Settings.flag4.mqtt_no_retain) {
	retained = false; // Some brokers don't support retained, they will disconnect if received
	}