chore: Reduce delta on ports to blockly-samples (#6886)

* Reduce usage of obsolete .keyCode property.
* Rename private properties/methods which violate eslint rules.
* Use arrays of bound events rather than individual properties.
* Improve typing info.
* Also fix O(n^2) recursive performance issue in theme's getComponentStyle function.
* And replace String(...) with '${...}' (smaller, faster).
* .toString() is considered harmful.

tests/mocha/webdriver.js

@@ -30,7 +30,7 @@ async function runMochaTestsInBrowser() {
     ],
     logLevel: 'warn',
   };
-  
+
   // Run in headless mode on Github Actions.
   if (process.env.CI) {
     options.capabilities['goog:chromeOptions'].args.push(