Feature request: Add AEAD algorithms

**Is your feature request related to a problem? Please describe.**
Authenticated Encryption with Associated Data (AEAD) algorithms are widely used. I've used CyberChef for experimenting with cryptography, and this seems like a pretty major oversight.

**Describe the solution you'd like**
Support for AEAD algorithms, such as AES-EAX.

**Describe alternatives you've considered**
I've copied and pasted data from CyberChef into a Python script (using the PyCryptoDome library) for handling AEAD, then copied the results back to CyberChef.

**Additional context**
I'd be happy to try my hand at implementing this, but I am new to this repo so someone more experienced would likely be able to handle this far faster than I can. If I'm able to get it working, I'll treat this as a "tracking" issue.

Start by reviewing CyberChef's existing encryption operations and their tests, then compare their conventions with the requested AEAD behavior. Confirm the initial algorithm scope, including how associated data and authentication results should be handled, with maintainers. Done means the agreed AEAD algorithms work in CyberChef and have coverage for their expected inputs and outputs.

Written by the indexing model from the issue text.