Generate map previews for RA1 and TD maps

[Metadorius]

Currently the client can parse only RA2 and TS maps which have map previews embedded in them already. RA1 and TD maps don't have such map previews, hence the need to parse the map contents and draw a bitmap for them.

This was already implemented by Iran (@mvdhout1992) as a standalone application: https://github.com/mvdhout1992/RedAlertMapPreviewGenerator Refactoring his code, testing if it works on TS maps and embedding it would be the most simple solution.