RFC: MSTACK Toasts

[EntranceJew]

Is your feature request related to a problem? Please describe.

• MSTACK spams a lot of messages which disappear relatively quickly.
• Counter-intuitively, it also quickly fills the screen with information that can limit visibility.
• The MSTACK should have an ability to refresh existing notifications to minimize noise.

Describe the solution you'd like

Goal

• The player gets a notification on a subject.
• When a new notification on the same subject arrives, it "refreshes" the message timer and visually moves up the stack.

Implementation

An API similar to:

local uuid = MSTACK:AddMessage("win_showreport")

-- some time in the future:
MSTACK:UpdateMessage(uuid, "round_begintime")

-- further still:
MSTACK:UpdateMessage(uuid, "round_selected")
MSTACK:UpdateMessage(uuid, "round_started")

or something like:

-- completely hypothetical server-sided code:
notif.Push("round_state", "round_begintime")

-- later:
notif.Push("round_state", "round_selected")
notif.Push("round_state", "round_started")

which on the client, would manifest as:

MSTACK.keys = {}

local function notif()
  local key = net.ReadString()
  local msg = net.ReadString()
  local uuid = MSTACK.keys[key]
  if uuid then
    MSTACK:UpdateMessage(uuid, msg)
  else
    MSTACK.keys[key] = MSTACK:AddMessage(msg)
  end
end
net.Receive("ttt2_notif_push", notif)

or more likely something to do with MSTACK.msgs

Describe alternatives you've considered

• ripping out things and replacing it with netmessages

Additional context

More difficult, as most of the MSTACK stuff has it, traces through exclusively client code:

EndRound
LANG.Msg
LANG.ProcessMsg
LANG.ShowStyledMsg
LANG.Styles

Which, as an aside, makes it extremely difficult to send a client a message in their native language which includes parameter tokens that are also interpreted from their native language (e.g. a weapon name inside a notification regarding the weapon they're trying to lift originating from the server, referring to another language string -- this requires a lot of single-purpose netmessages that serve the same goal).