Improve automatic tree-shaking

[hfournier]

Describe the bug
When building an Angular project that uses class-validator, Angular generates a large number of warnings regarding CommonJS dependencies.

As you can see in the example below, I can simply import from class-validator without explicitly having to specify class-validator/esm2015.

import { IsEmail } from 'class-validator';

The bundling will automatically use \node_modules\class-validator\esm2015.
However, it is not automatically using \node_modules\validator\es, which results in all the warnings (see below).

A solution is suggested by @NoNameProvided in this thread.

Examples

Warning: C:\Users\Me\Documents\MyProject\node_modules\class-validator\esm2015\decorator\string\IsEmail.js depends on 'validator/lib/isEmail'. CommonJS or AMD dependencies can cause optimization bailouts.
For more info see: https://angular.io/guide/build#configuring-commonjs-dependencies

The above warning is generated for every validator, whether it's used or not.

Additional context
Validator.js version: 13.6.0
Node.js version:
OS platform: windows 10

Angular CLI: 12.2.7
Node: 14.17.0
Package Manager: npm 6.14.7
OS: win32 x64

Angular: 12.2.7
... animations, cdk, cli, common, compiler, compiler-cli, core
... forms, language-service, material, platform-browser       
... platform-browser-dynamic, router

Package                         Version
---------------------------------------------------------
@angular-devkit/architect       0.1202.7
@angular-devkit/build-angular   12.2.7
@angular-devkit/core            12.2.7
@angular-devkit/schematics      12.2.7
@schematics/angular             12.2.7
rxjs                            6.5.5
typescript                      4.3.5

[tux-tn]

Thank you for your suggestion @hfournier

We are already discussing this in #683 , please use that issue if you have any addition concerning tree-shaking/es6 imports.