Support CommonJS modules & npm packages in ts_devserver & ts_web_test_suite

[gregmagolan]

🚀 feature request

Relevant Rules

ts_devserver, ts_web_test, ts_web_test_suite, karma_web_test, karma_web_test_suite

Description

Right now to use commonjs modules or npm packages in ts_devserver (and other rules) you need to transform the modules to named UMD or named AMD manually using a tool such as browserify. An example of this transform is: angular/angular-bazel-example#343.

Describe the solution you'd like

A general solution is needed so that if ts_devserver has a direct or transitive dependency on an npm package such as @npm//date-fns it will just work without any extra work required by the user. This solution should also handle deep imports such as import * as factory from 'date-fns/factory' where possible.

[gregmagolan]

#725 partially solves this as it provides a browserify generated @npm//node_modules/foobar:foobar.umd.js and @npm//node_modules/@foo/bar:bar.umd.js targets for use in ts_devserver and other rules. Propagation of these targets to these rules is not automatic yet as browserify on the "main" will likely not work for all npm packages.

[gregmagolan]

Closing with #725