Fixes IV calculation for AES-GCM mode

[heeeyflo]

What does this PR do?

• Code changes

This PR fixes an issue with the IV calculation that was caused by an incorrect writeUIntBE function call. It includes basic unit tests for Cipher & Decipher that cover most of the encryption modes available in Bun at the moment.

1. IV fix comes from this PR to browserify/browserify-aes.
2. Some of the unit tests are adapted from the nodejs/node.

How did you verify your code works?

• I ran make js and committed the transpiled changes
• I or my editor ran Prettier on the changed files (or I ran bun fmt)
• I included a test for the new code, or an existing test covers it

[dylan-conway]

Thank you!