Add unionUndefined options for exactOptionalPropertyTypes

[kahirokunn]

In environments where exactOptionalPropertyTypes introduced in typescript 4.4 is enabled, there will be many situations where you want to union undefined for parameters with a questionToken.

https://www.typescriptlang.org/docs/handbook/release-notes/typescript-4-4.html#exact-optional-property-types---exactoptionalpropertytypes

If PR are merged in oazapfts or forked, this can be implemented, what do you think?
oazapfts/oazapfts#219

[kahirokunn]

@phryneas what do you think? 👀

[kahirokunn]

@msutkowski what do you think? 👀