Adds a universal way to get thumbnail images.
- `thumb:entities/sents/npc/scientist.sent` - resources/assets
- `thumb:mount://ns2/ns2/models/effects/exosuit_part1.model.vmdl` -mount files
- `thumb:facepunch.snowman` - packages
This greatly simplifies UI like the spawnmenu that needs to show thumbnails for these things.
We also add `AssetTypeFlags.IncludeThumbnails`. If this is set then when the package is published, any asset types with this flag will include a "[path].c.png" thumbnail image of it.
Also does Api++ protocol increase.
* Impact damage system added to Rigidbody
* Fix Rigidbody Velocity and AngularVelocity not getting applied if object wasn't created yet
* Props only ignite from impact damage if it's significant
* Fix gibs not properly inheriting parent object velocity
