Activate verbatimModuleSyntax on typescript configuration

See https://www.typescriptlang.org/tsconfig/#verbatimModuleSyntax

This option makes the compiler fail when types are imported or exported without being explicitly marked as types.
This is useful both for developers who can more easily understand what code will be bundled and what is just types.
In the same way, this is useful for the bundler (Vite) that can more efficiently identify what is actual code to bundle.