Stricter typescript definitions

[lwolle]

The typescript definitions are a big help already, but on first sight they could be much stricter, and thus make development safer.

For example, the Event-type form @uppy/core resolves to
type Event = LiteralUnion<'file-added' | 'file-removed' | 'upload' | 'upload-progress' | 'upload-success' | 'complete' | 'error' | 'upload-error' | 'upload-retry' | 'info-visible' | 'info-hidden' | 'cancel-all' | 'restriction-failed' | 'reset-progress' | string & { }; which seems not quite ideal to me. This could to this exaggerated erroneous call to uppy.on: uppy.on('upload-errrOOOoooOOOOOrrrr'. Therefore I'd suggest to make these types stricter, and in the same run remove all the most of the any-types if possible

[Murderlon]

hi @lwolle, thanks for the suggestion. Stricter types are always a good idea and it's an ongoing effort. If there is anything in particular you'd like to quickly change, PRs are welcome :)