feat(library/kernel_bindings): improve Fun/Pi Lua APIs

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
feat(library): add simple normalization procedure

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
feat(library/kernel_bindings): add normalize, whnf, type_check, infer_type methods to environment object Lua API

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
test(lua): add test for mutually recursive inductive type recursor/eliminator

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>