[Editor & Engine] Implement support for texture atlases

[Wohlstand]

Allow to use same texture by multiple objects, but various parts of it.

This feature will allow next abilities:

• Have different-size objects based on same texture that cropped in dependence of element size
• Support of "GFX Extension" feature of 38A standard

What needed

• add x, y, width and height fields per blocks, BGOs, terrain, paths, sceneries, level entrances, and x, y per NPC into the INI files
• by default (x, y, width, height) are must be equal zero or less, then use auto-size captured from texture image metrics.
• Provide UI into the editor to choose texture part from the atlases.