Typescript types don't work --isolatedModules flag

Trying to compile with 4.0.0-alpha.32 and I get errors about ambient constant enums.

Will to take a look at PR for this one.

Logs below:

../../node_modules/babylonjs-gltf2interface/babylon.glTF2Interface.d.ts:15:16 - error TS1209: Ambient const enums are not allowed when the '--isolatedModules' flag is provided.

15     const enum AccessorComponentType {
                  ~~~~~~~~~~~~~~~~~~~~~

../../node_modules/babylonjs-gltf2interface/babylon.glTF2Interface.d.ts:44:16 - error TS1209: Ambient const enums are not allowed when the '--isolatedModules' flag is provided.

44     const enum AccessorType {

...
                  ~~~~~~~~~~~~

There is about 100 of these.

pinging @sebavan

Can you try without --isolatedModules ?