Allow use of components within Wrapper for unit tests

[cnotv]

Description

Change configuration to avoid manual cast of Wrapper<YourComponent> to access wrapper.vm.

Context

Currently if a developer needs to access to a wrapper.vm to get computed or data values or other component properties, it's necessary cast manually the component type to it. This however also causes issues on build and we are forced to use the following code:

const wrapper = shallowMount(YourComponent as unknown as ExtendedVue<Vue, {}, {}, {}, DefaultProps>, {

This may require the use of a custom tsconfig as defined in the docs.

[catherineluse]

It would be nice if there was a reusable, generic translation wrapper that could be used for all Rancher components that get moved into the component library if they also have text that needs translation.

[cnotv]

@catherineluse I have already added the global variable and the directive, but unfortunately the translation is a getter from the state and we should not add globally the state for each test. If we do so, it would include also basic components as buttons and functions from the utilities.
Furthermore, in each case where we mock the state, it will be required to rewrite the i18n getter as well.

This is another case where faulty architecture choices could be easily identified by writing tests :)

I would rather suggest to replace that logic in somehow.

PS: This issue is meant to extend the styling of the component, so even if we could, it would require an issue on its own.