Add an option to save level （LVL format） with UTF-8 format

[LoveBodhi]

Since moondust doesn't save .lvl formatted level with UTF-8 format (especially there're Chinese characters) on my machine (I'm in Windows 10, with Chinese locale), I have to use SciTE to fix that. I suggest this option because TheXTech require UTF-8 format for these fields.

[Wohlstand]

Levels of legacy LVL format historically never supported UTF-8, basically local ANSI charset was been used. I have another task to allow choice ANY source or target charset for LVL files so that will be controllable.

[LoveBodhi]

Levels of legacy LVL format historically never supported UTF-8, basically local ANSI charset was been used. I have another task to allow choice ANY source or target charset for LVL files so that will be controllable.

Okay, When I play this episode https://smbxarchive.wohlsoft.ru/SMBX%201.3/Mario%20RPG%282013%20Update%29.rar with TheXTech, error occurs:

I think I should convert these to LVLX instead...