When ThemeContext.Extend is a child of a custom Box component with
a ref prop, the ThemeContext seems to lose the base theme.
This happen only during tests, so with the jsdom environment. So
if the base theme is undefined, we set it again to pass the test.

Some labels have to be translated again because of the change
to the Cunningham Select component. We change the id of the
label to help to find the one's that have to be translated.

When we refactorized the buttons, the design of the buttons
when we ask the username before to access a classroom was not
good. We improve the design of the buttons.

In order to do the transition to the cunningham design system,
in lti, we replace the grommet Box component with our
custom Box components.

In order to do the transition to the cunningham design system,
in lib-component, we replace the grommet Box component with our
custom Box components.
To adapt with the changes in lib-component, we also have to change
some components apps and other packages.

In order to do the transition to the cunningham design system,
in lib-classroom, we replace the grommet Box component with our
custom Box components.

In order to do the transition to the cunningham design system,
in lib-markdown, we replace the grommet Box component with our
custom Box components.

In order to do the transition to the cunningham design system,
in lib-video, we replace the grommet Box component with our
custom Box components.

The grommet theme colors are correctly displayed only by grommet
components, we change the color of the grommet components to the
cunningham color.