feat(client): initial POC of smart_equation

[maqi]

Description

Initial POC of SmartEquation, which using Pointer pointing to a chunk.
This can be used to replace part of the quote verification flow: get a cost based on the QuotingMetrices
To be the sole place holding the equations of how to calculate the cose, which doesn't need to use smart_contract.

The PR contains an E2E test to demo that:

1. publish an equation of a + b to the network
2. fetch the equation and use it to calculate
3. update the equation to (a+5)*b
4. fetch the equation from the network again and use it to calculate (result shall be new)

This answers one concern in the original native notken re-introduction RFC regarding having a smart_contract styple quoting verification.
This also shows a potential that with further design and expansion, we could have a non-block-chain-based smart_contract