[Ohrrpgce] SVN: teeemcee/13405 Add GfxSettings.screenshot_format (for gfx_directx)

[subversion at HamsterRepublic.com]

teeemcee
2023-12-15 02:03:27 -0800 (Fri, 15 Dec 2023)
283
Add GfxSettings.screenshot_format (for gfx_directx)

Also, the ImageFileTypes enum is in gfx.bi/h now and includes .DDS and is used
by gfx_directx for getting/setting screenshot format with gfx_SendMessage, so
the mapping for formats to values has changed, but was and is never used.
---
U   wip/allmodex.bas
U   wip/allmodex.bi
U   wip/gfx.bi
U   wip/gfx.h
U   wip/gfx_directx/gfx_directx.cpp