demo,scripts,test: move legacy demo scripts into extra, remove hardhat config

hardhat.config.js

-/**
- * @type import('hardhat/config').HardhatUserConfig
- */
-
-require("@nomiclabs/hardhat-ethers");
-require("hardhat-gas-reporter");
-const fs = require("fs")
-
-// attempt to read private key
-let private = "0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80"
-try {
-  private = fs.readFileSync(process.env.HOME+"/.privatekey").toString().strip()
-} catch {
-}
-
-
-module.exports = {
-  //defaultNetwork: "hosthat",
-  networks: {
-    l1: {
-      url: "http://127.0.0.1:8545/",
-      accounts: ["0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80"],
-      timeout: 600_000,
-    },
-    l2: {
-      url: "http://127.0.0.1:9545/",
-      accounts: ["0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80"],
-      timeout: 600_000,
-    },
-  },
-  solidity: {
-    version: "0.7.3",
-    settings: {
-      optimizer: {
-        enabled: true,
-        runs: 200
-      }
-    }
-  },
-};

package.json

-{
-  "dependencies": {
-    "@nomiclabs/hardhat-ethers": "^2.0.5",
-    "@types/node": "^17.0.31",
-    "chai": "^4.3.6",
-    "ethereum-waffle": "^3.4.4",
-    "ethers": "5.6.1",
-    "hardhat": "^2.6.5",
-    "hardhat-gas-reporter": "^1.0.8",
-    "rlp": "^3.0.0",
-    "typescript": "^4.6.4"
-  }
-}