[testing] cover more cases for integration tests

[extraymond]

Info

description:
For essentials features for smart contracts, and features relying on runtime integration through system libraries and chain-extension, there should be a suite of tests to make sure they are correct for all times

expected results:

• restructure tests for basic smart contract features, separate ink and solidity specific if any
• maintain cross contract tests in 4 direction for the combination from ink and solidity
• for every chain-extension, maintain contract tests for each ink/solang
• provide instruction for ecosystem projects integration to integrate their project in the tests