Resolves #1204 (gif export, no strip export)

Description

More backports from [you know the drill].

• ImportGraphicsWithParametersPlus.csx is basically ImportGraphics but it can import GIFs, strips, single image files and set sprite origins and animation speeds.
• ExportSpritesAsGIF.csx does exactly what it says on the tin. It uses the animation speed set in the IDE for GMS2 games. Thanks ImageMagick!

UTMTCE adds a few other scripts but those were fully made by other people so I don't want to include them here, and especially GIF sprite support is a pretty requested feature.

Caveats

• ImportGraphicsWithParametersPlus only allows you to set the properties for all sprites at once, not individually. It also doesn't let you set specific offsets, only the corners/edges/center.
• ExportSpritesAsGIF defaults to a fixed 30fps for GMS1 games, and that might need to be changed? (if we want the user to be able to set the framerate, for instance)

Notes

ImportGraphicsWithParametersPlus could probably replace ImportGraphics entirely, though I didn't because it adds the extra dialog to set the sprite properties. (I'd be 100% down to have it replace ImportGraphics though, if that's not an issue)

I'm on a UTMTCE merging spree lol. At this point it has like, only 2 unique features left that could be merged into UTMT. Here's the total diff, though it's a bit messy due to random other changes scattered around.