feat: create and test `LSP26FollowingSystem`

[b00ste]

What does this PR introduce?

This PR replaces #961

🚀 Feature

This PR introduces smart contracts for LSP26FollowingSystem with functionality and gas tests. To check gas results check packages/lsp26-contracts/gasCost.json.

PR Checklist

• [x] Wrote Tests
• [ ] Wrote & Generated Documentation (readme/natspec/dodoc)
• [x] Ran npm run lint && npm run lint:solidity (solhint)
• [x] Ran npm run format (prettier)
• [x] Ran npm run build
• [x] Ran npm run test