fix(type-compiler): include enum annotations in .d.ts transformation

[kuesutodev]

Summary of changes

Exported enums seem to not generate __Ω annotations in their respective .d.ts files. This leads to Symbol ___Ω not found in... type errors when other packages want to use those definitions.

Adding this check seems to have the desired effect and looks like one of the other checks above: https://github.com/deepkit/deepkit-framework/blob/master/packages/type-compiler/src/compiler.ts#L910

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