support simple dynamic paths in dynamic imports

[ju1ius]

Hi,

This is a follow-up to #216.

Currently transforming the following:

const getCommand = async (name: string): Command =>
  (await import(`./commands/${name}.ts`)).default

yields the following result:

const getCommand = async (name) =>
  (await import(`./commands/${name}.ts`)).default

While I understand full support for dynamic paths is unsolvable, could the transformer support simple cases like this (either by inspecting the argument's AST or via a special annotation like webpack does) ?