Support for TSC verbatimModuleSyntax

[stephenjason89]

I am getting a lot of ts error because types need to be imported with import type { ConvParams, SeparableConvParams } from '../common/index'; instead of import { ConvParams, SeparableConvParams } from '../common/index';

241 errors

Thank you for maintaining this package

[vladmandic]

this is valid item, but to update entire repo to use strict verbatimModuleSyntax is non-trivial and I don't have time in the near-future.

however, if you want to submit PR, it would be welcome.