Previously, the context for `options.{before,after}Each()` functions was
isolated from the context created by the odoo `test` function, making
it impossible to save attributes in the test during
`options.beforeEach()` that are accessible from the test itself, or to
clear resources created in the test in `options.afterEach()`
Moreover, the odoo test infrastructure was set up completely inside the
test wrapper, after `options.beforeContext()` had already run, making
it impossible for `options.beforeContext()` to use this infrastructure.
Here we use the QUnit context directly in the test, but move the
initialization previously done in the test wrapper to a `beforeEach`
wrapper (and, symetrically, on `afterEach`), making it possible to use
the odoo infrastructure in the javascript test setup, including
declared section dependencies.