Wrong options type when set from environment variables

Hello.

While I was implementing PR: https://github.com/parse-community/parse-server-s3-adapter/pull/117, I encountered a problem with the environment variables.

As you can see in the image below, the _baseUrlDirect variable has the correct type (boolean), as it was not set via the environment variable. However, the other two _directAccess and _presignedUrl variables that were set as environment variables, are not being converted to the correct type (it should be boolean).

This problem causes a check of the form if (_directAccess) { ... }, do not be verified as expected.

I would like to know if I can create a PR using the https://www.npmjs.com/package/boolean lib to do this conversion?

I don't know if you noticed, but the _presignedUrlExpires variable should be an integer, but it is also a string. However, this case can be solved with the standard parseInt() Javascript library.

Start by tracing how _directAccess, _presignedUrl, and _presignedUrlExpires are read from environment variables in the adapter, and compare them with the correctly typed _baseUrlDirect value. Check the proposed boolean library alongside standard integer parsing. Done means boolean environment values control the checks as expected and _presignedUrlExpires is treated as an integer.