Feature request: Decimal RSA

**Is your feature request related to a problem? Please describe.**
While the current implementation of the RSA feature is great for more real-life RSA problems, it would be incredibly helpful if cyberchef also supported RSA with decimal or hex values, instead of PEM encoded keys.

**Describe the solution you'd like**
In order to not have to reimplement RSA decrypting and encrypting again, an operation allowing the creation of either a public or private key from the given RSA variables would integrate with the current set of tools

**Describe alternatives you've considered**
A new implementation of decrypting rsa with p, q, c, and e or d, ct, and N and encrypting RSA with pt, n, and e.

Start by reviewing CyberChef’s current RSA implementation and existing encryption/decryption operations. Clarify the required inputs for public and private keys, including the listed decimal or hexadecimal variables, and whether key construction should be separate from encryption and decryption. Done means the scope and expected behavior are defined without requiring a separate RSA implementation.

Written by the indexing model from the issue text.