chore: migrate to TypeScript

[gclapperton]

What does this PR do?

Migrates the library to TypeScript. Note: this PR is about enabling TypeScript and not leveraging it. Where the compiler complained about types, I just added any... for now. And it does also not yet generate type declarations. This was done intentionally as I didn't want to break consumer if they started relying on them while they were still being in flux

• imports/exports have been switched to ESM
• .npmignore has been deleted in favour of explicitly specifying files to be included using the files key in the package.json
• formatted with nom run format (prettier)

How should this be manually tested?

npm run test to make sure that the library is not broken npm pack to see what will be in the published package

npm link and then npm link snyk-policy in Registry before running Registry tests to make sure the clients can still consume the library and everything is working as expected

[snyksec]

:tada: This PR is included in version 2.0.0 :tada:

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot :package::rocket: