Remodel Many Autotilesets as Autotileset-Corners

[Eauix]

Many tilesets have layouts whose autotilesets would work better as autotileset corners (similar to the snow and forest background tilesets present in levels). So, this request is focused on rewriting A LOT of autotilesets in the form of corners, so they are drawn in a more natural and less annoying or broken way.

Rewritten autotilesets on Worldmaps:

• Every "Land" and "Ceiling" tileset
• Thin ice, Snow Layers, Ice Holes, Trees and other embellishment tiles.

Rewritten autotilesets on Levels:

• Every "Hole" tileset
• Snow Unisolid 1 and 2
• Forest and Corrupted Forest Bushes

Tweaks and New Features:

• Extra tile images for Worldmaps
• Updated Worldmap strf
• Extra tile images for Levels
• Updated Level strf
• Autotileset for Poles and Goals
• Lightmap tiles for Worldmaps
• Autotiles for some more Worldmap decorations (Cave pillares, forest bushes, rocks, crystals and lily pads)
• Autotilesets for Lightmaps
• Rename some autotilesets
• Move some tiles to background tilegroups
• (Experimental) Autotiles for Diagonal Poles

Notes:

• The corrupted_forest_transition autotileset will not be made into an autotileset-corner, because they do not interfer on tiles from other autotilesets, and this transition works better by replacing forest tiles.

• The "Hole" autotilesets will no longer be rewritten as corners due to an issue where a tile that is present both in an autotileset and in an autotileset-corner doesn't change properly when erasing.

• Update: the issue has been fixed, so they will be rewritten

[Eauix]

It's ready

[Frostwithasideofsalt]

gonna review this

[weluvgoatz]

Looks good from what I tested!