Display panel should be unlocked with a separate red science research

[jDomantas]

Proposal: there should be a research costing 10-20 red science which unlocks display panel. Display panel would be removed from circuit network research.

Arguments:

1. Display panels have a full proper use even without circuit network. It was even how they were introduced in fff-419 - as a way to show icons and messages, or leave notes to other players. The circuit connectivity is just a bonus that lets you do much more cool stuff with it, which applies to most other entities.
2. Tools of communication (of which display panel is pretty much the only one) should be available early in the game. And I think those tools of communication are most useful for new players, for whom green science is not really that early in the game.
3. I feel that circuit network research is a bit bloated and unlocks too many things, and possibly feels a bit intimidating for players who are not familiar with it. Moving display panels out would make circuit network research feel "smaller".
4. This could of course be easily done in a mod, but I think it would be better to have it by default (i.e. in vanilla). Players who know what display panels would not have a problem with researching circuit network (otherwise they wouldn't know what display panels are), and thus would have no need for it. Players who do not know about display panels wouldn't look for a mod that changes them.

My own experiences in which I wanted this change:
1. When playing on public servers which reset often-ish. A relatively large amount of time is spent in the early game, and circuit network can be considered unimportant research (especially in combat oriented maps). An early and cheap way to leave notes for other players would be useful.
2. When inviting friends to play multiplayer to introduce them to factorio. My favorite way to play that is by letting friends work on science automation while only providing tips/hints/tutorials, and myself working on supporting tasks. If display panels could be unlocked by handcrafted science packs it would let people leave written notes without rushing through red/green science automation. A mod of course would be a workable solution in this scenario, but I feel that it's better to avoid mods when introducing new players to the game.