Gigi Files

WebGPU: * Extensions are opt-in from the editor now, instead of always being asked for. Helps techniques work on more devices by default. * Makes boolean variable default values into JavaScript safe values, like it does for floats. * Does string replacement in shader header files like it does on other platforms - limited to const variables and similar * Better instructions in the todos about how to load textures * Imported textures now have a URL box in the HTML instead of requiring you to write JavaScript * Fixed error reporting when loading textures

Viewer: * Log window and shader list improvements (thanks Martin!) * Fix for mesh/amplification shader dispatch logic

Editor: * Shader resources will show only buffer or texture settings, whichever was chosen for the type

Compiler: * Better sanitization of identifiers made from node names / variable names / etc. in generated code.