refactor!: use named destr export

[pi0]

This PR changes default export of destr to named export:

-- import destr from 'destr'
++ import { destr } from 'destr'

-- const destr = require('destr')
++ const { destr } = require('destr')

The implementation uses backward compatible CJS reexports so usually there shouldn't be breaking changes but still will be only applied in destr v2.

This change is necessary to introduce more named exports without future conflicts.