Update Vue to 3.3.4

[matthew-white]

This PR updates Vue to the latest version. I had to wrangle npm a little to make the update happen, but I was able to do so: see the commit message for details.

In #830, I thought I had tested my change against the latest Vue. However, while I had run npm update vue, I don't think I confirmed that the update was successful, so I actually wasn't running against an updated Vue. When I did manage to update Vue, I saw an error that seems related to the change in #830. Here's part of the error:

WARN LOG: '[Vue warn]: Property "$container" was accessed during render but is not defined on instance.', '
', ' at <I18nT', 'tag="li"', 'keypath="introduction[1].full"', '>', '
', ' at <Modal', 'state=false', 'hideable=""', 'backdrop=""', ' ...', '>', '
', ' at <ProjectSubmissionOptions', 'state=false', 'onHide=fn', '>', '
', ' at <FieldKeyList', 'key=0', 'projectId="1"', 'onFetchProject=fn<bound fetchProject>', ' ...', '>', '
', ' at <AsyncRoute', 'componentName="FieldKeyList"', 'props=', Object{projectId: '1'}, 'loading="tab"', ' ...', '>', '
', ' at <RouterView', 'onFetchProject=fn<bound fetchProject>', 'onFetchForms=fn<bound fetchForms>', 'onFetchFieldKeys=fn<bound fetchFieldKeys>', '>', '
', ' at <PageBody>', '
', ' at <ProjectShow', 'key=2', 'projectId="1"', '>', '
', ' at <AsyncRoute', 'componentName="ProjectShow"', 'props=', Object{projectId: '1'}, 'loading="page"', ' ...', '>', '
', ' at <RouterView>', '
', ' at <App', 'ref="VTU_COMPONENT"', '>', '
', ' at <VTUROOT>'
...

  FieldKeyList
    ✗ toggles the "Submission Options" modal

I don't have a good explanation for why this test of FieldKeyList fails, but tests before FieldKeyList pass. Maybe because FieldKeyList renders ProjectSubmissionOptions, which accesses $route in its template? Could it be that $container, which is a Vue Test Utils mock, isn't being injected until later in the component's lifecycle compared to before?

Ultimately, I don't think it's very important that we understand this error. Instead of computing $router based on $container, we can copy the global property to each component. That way, components won't ever be accessing $container; only tests will. When I make that change, tests pass again.

Before submitting this PR, please make sure you have:

• run npm run test and npm run lint and confirmed all checks still pass OR confirm CircleCI build passes
• verified that any code or assets from external sources are properly credited in comments or that everything is internally sourced

[matthew-white]

I think this works because $router is a property on the prototype chain. By assigning it to this, we give this its own $router property. The vm property of the Vue Test Utils wrapper seems to provide access to an instance's own properties, but not global properties.

[matthew-white]

We don't assign $route to this like we do with $router because the value of $route can change (whenever there's a navigation and the route changes). Unlike $router, $route as a global property seems to be a getter: https://github.com/vuejs/router/blob/a1611b6099403cfe9539ee8d4e9308b3a6a0175c/packages/router/src/router.ts#L1211-L1215

[sadiqkhoja]

looks good