TSLint → ESLint (#21006)

* Alphabetized tslint and tsconfig files

* Optimized tsconfig files

* Optimized editorconfig & prettier config files

… to reduce redundancy

* Switched to @grafana/tsconfig

… and:
* de-duped options
* removed options with default values

* Fixed nasty issue with types for nested slate-react

* Replaced TSLint with ESLint

* TSLint disables → ESLint disables

… also JSHint removals, which haven’t had an affect since it was replaced with TSLint.

* Compliances for ESLint, Prettier and TypeScript

* Updated lockfile

scripts/webpack/webpack.dev.js

@@ -69,10 +69,10 @@ module.exports = (env = {}) =>
               },
             },
             {
-              loader: 'tslint-loader',
+              loader: 'eslint-loader',
               options: {
-                emitErrors: true,
-                typeCheck: false,
+                emitError: true,
+                emitWarning: true,
               },
             },
           ],