Explore new JavaScript test framework

[wkurniawan07]

To support browser-based QUnit tests like we are doing now, we have to bundle all the test files (and also production files) into one with Webpack, run all tests together, and read the test report including coverage. This workflow has many drawbacks (and it doesn't help that our JS code has almost 100% coupling to the DOM structure):

• There is no way to run a single unit test
• The "coverage" reported includes the extraneous codes added by Webpack
• The fact that we need to bundle the test files and have the dev server up before running the tests means (unnecessary) extra effort spent

We need a new test framework which (1) allows single test runs and (2) does not necessitate bundling.

[wkurniawan07]

Resolved in V7.