Issue MPT with Metadata (Python)

Creates a sample MPT issuance with metadata encoded as JSON according to the XLS-89 standard.

Quick setup and usage:

python -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt
python issue-mpt-with-metadata.py

The script should output a validated transaction and end with a line such as the following:

MPToken created successfully with issuance ID 0050773D6B8DF8C6BEA497016C8679728A217DE1C4D50AC5.