Move all config definitions to their respective modules

Modules/Messenger.lua

@@ -2,6 +2,11 @@ local _, shared = ...
 ---@cast shared HeimdallShared
 local ModuleName = "Messenger"
 
+---@class HeimdallMessengerConfig
+---@field enabled boolean
+---@field debug boolean
+---@field interval number
+
 ---@class Message
 ---@field message string
 ---@field channel string