Lua console: Add a prelude file

[glebm]

Runs lua/repl_prelude.lua at console initialization.

The default prelude contains global assignments for all devilutionx modules. This should save us on typing.
The console has its own environment so this doesn't affect other Lua scripts.

[AJenbo]

Please show an example of how to use render.string 😭

[glebm]

It works for me even without the prelude:

Of course calling it once does nothing, you'd have to do it on every frame, for example here is my user.lua:

local log = require("devilutionx.log")
local render = require("devilutionx.render")
local message = require("devilutionx.message")

local function greet ()
  message("Hello from " .. _VERSION)
  print("Hello from ", _VERSION)
end
Events.OnGameStart.Add(greet)

local function drawGreet ()
  render.string("Hello from " .. _VERSION, 10, 40)
end
Events.OnGameDrawComplete.Add(drawGreet)

[glebm]

@AJenbo Rebased and added inspect and audio