Can't decrypt large notes with Whisper Note ( 200,000 characters + )

[Tillbilly]

Maximum Call stack exceeded in decryption algorithm.

Edge got to between 600kb and 800kb

Chrome failed at 200kb.
Decryption failed due to: RangeError: Maximum call stack size exceeded.

We should either limit the number of characters in the note to something reasonable ( 50,000 ) or address the recursion in the algorithm.

In the case of a limit, the instruction help text should be updated to reflect this.