Provide intelligence in JSDOC import statements

[kieferrm]

With TS 2.9 I now can write

/**
 * @typedef {import("./dir/file1").exportedType} typeAlias
 */

We should provide support for completing the file paths parameters for import the same way we do for require.

[mjbvz]

Thanks. Opened microsoft/TypeScript#25275 to track this upstream