fix prettier by removing type imports

[JackCA]

prettier 1.* does not support typescript 3.8's type imports so the following error would occur when prettier was run:

["ERROR" - 3:43:40 PM] '=' expected. (1:13)
> 1 | import type { Request, Response } from 'express';

This is also what's causing the current CI failure.

tsdx has not upgraded to prettier 2.* yet so we cannot use type imports yet.

See jaredpalmer/tsdx#632 and prettier/prettier#7263

This doesn't seem to have any impact on build size.

Since prettier works now, there are other prettier-related fixes in this PR.

[mxstbr]

Thank you!!