chore: update package.json scripts for gn build and automated releases (#14612)

* Removes un-used and non-functional code coverage helpers
* Removes un-used release script aliases
* Moves TLS to a lib folder for cleaner directory structure
* Implements start.py as start.js for the GN build
* Adds a re-usable getElectronExec helper for future scripts
* Refactors spec runner to use the helper

script/start.js

@@ -0,0 +1,18 @@
+const cp = require('child_process')
+
+const utils = require('./lib/utils')
+
+const electronPath = utils.getAbsoluteElectronExec()
+
+var child = cp.spawn(electronPath, process.argv.slice(2), { stdio: 'inherit' })
+child.on('close', (code) => process.exit(code))
+
+const handleTerminationSignal = (signal) =>
+  process.on(signal, () => {
+    if (!child.killed) {
+      child.kill(signal)
+    }
+  })
+
+handleTerminationSignal('SIGINT')
+handleTerminationSignal('SIGTERM')