Initialize miner reward pool

[Neylix]

Description

This PR implement the initialization of the minser reward pool.
It uses the network pool seed of the shared secret chain to create a new transaction chain.
The first transaction is the creation of 1M NFT

Fixes #379

Type of change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

Run the node and there is the creation of the transaction during network init.
Also uses test files

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules