[RFC] Use module/method integer indexes

[jordy25519]

Simplify the encoding and retrieval of permission information within CENNZnuts.

Motivation

CENNZnuts encode module and methods names as strings. This gives ease and flexibility to encoders but pushes a significant cost and complexity to the CENNZnet runtime. e.g. current lookups require for loops, arbitrary length limits, string matching etc. which creates many possible exploits and edge cases. Storage is also costly.

Proposal

CENNZnuts should use the integer indexes for the modules/methods as used by the Call enum.
The chain already has helper functions to convert these indices to modules/methods.
The runtime version should be included to tie the certificate to the CENNZnet protocol version.

The key suggestion is to replace the current 32 byte vector keys for modules and methods with one byte u8 each.
The wildcard index '*' could be set to some reserved key such as 254