Add ClipboardHelper for clipboard operations

[prolic]

• Added ClipboardHelper.h and ClipboardHelper.cpp to implement clipboard functionality.
• Registered HsQMLClipboardHelper type in QML

This update allows QML to access clipboard operations through a C++ helper class, enabling text copying to the system clipboard.

[prolic]

@Kleidukos wanna review?

[Kleidukos]

I am honoured by the offer, but I am illiterate in C++ 🥲

[prolic]

@Kleidukos That's fine. Do you know any security by any chance?

https://github.com/futrnostr/futr/blob/f1306f5dda1e8ab65b5f239d58b7461e8bc679f3/src/Nostr/Encryption.hs

see https://github.com/futrnostr/futr/pull/21

I wrote this, but I have no clue what I am doing here hahahaha

it works though.....

[Kleidukos]

I can emit some recommendations, as I participate in the Haskell Cryptography Group, but nothing beats an audit. ;-)