refactor: rename `@mtkbuild` to `@mtkcompile` and `structural_simplify` to `mtkcompile`#3656

ChrisRackauckas merged 3 commits intoSciML:masterSciML/ModelingToolkit.jl:masterfrom

AayushSabharwal:as/mtkcompileAayushSabharwal/ModelingToolkit.jl:as/mtkcompileCopy head branch name to clipboard