StoreForward: replace "empty" by "text" and improve comments

[GUVWAF]

This will replace the currently unused "empty" variant of the StoreForward message to "text", such that clients know how to handle the history from the server. Technically a breaking change, but the "empty" variant was not used in the firmware.

Also updated some of the comments of other fields.

[andrekir]

@GUVWAF what do you think of having both a text_broadcast and text_direct oneOf added?

this way we can separate broadcasts from direct messages like the Delayed field was designed (below): text_broadcast we replace the to with the broadcast node number; text_direct is a DM for us.

we would then need to pick the oneOf based on packetHistoryTXQueue[packetHistory_index].to here

protobufs/meshtastic/mesh.proto

Lines 861 to 876 in 1fa7252

	enum Delayed {
	/*
	* If unset, the message is being sent in real time.
	*/
	NO_DELAY = 0;
	/*
	* The message is delayed and was originally a broadcast
	*/
	DELAYED_BROADCAST = 1;
	/*
	* The message is delayed and was originally a direct message
	*/
	DELAYED_DIRECT = 2;
	}

[GUVWAF]

Good idea. Or should we add two RequestResponse tags instead? One for text_direct and one for text_broadcast? Currently I'm using the UNSET.

[andrekir]

Good idea. Or should we add two RequestResponse tags instead? One for text_direct and one for text_broadcast? Currently I'm using the UNSET.

commented on meshtastic/firmware#3194 (comment)