Console: support original prefixes

A user reported:
> Anyway, I figured console commands would help me, but anytime I try to use them I get an 'invalid syntax' kind of error.
>
> As for the cheat, I just want to spawn the character. I both typed out and copy/pasted this: CLUAConsole:CreateCreature("UDSOLA01")
> I saw that EE may use the entry C:CreateCreature("UDSOLA01") instead. Could that work in gemrb? Tech stuff isn't really my forte.

We could strip all [these prefixes](https://gibberlings3.github.io/iesdp/appendices/index.htm) (see CLUA Console subpages for the prefixes, eg. `CLUAConsole:`, `ctrlaltdelete:`) from the originals before parsing the command for real, just so it's more likely to work if anyone else tries, since many of the commands do have analogues in GUIScript functions.

It's all in gemrb/GUIScripts/Console.py.

Start by reading gemrb/GUIScripts/Console.py and locating where console input is parsed after the original command is received. Review the linked CLUA Console prefix pages, including CLUAConsole: and ctrlaltdelete:. Done means commands using those original prefixes are accepted before the existing command parsing takes place.

Written by the indexing model from the issue text.