fix: augment vue rather than @vue/runtime-core

[danielroe]

What kind of change does this PR introduce?

• Bugfix
• Feature
• Documentation
• Code style update
• Refactor
• Build-related changes
• Other, please describe:

Does this PR introduce a breaking change?

• Yes
• No

The PR fulfills these requirements:

• It's submitted to the dev branch (or v[X] branch)
• When resolving a specific issue, it's referenced in the PR's title (e.g. fix: #xxx[,#xxx], where "xxx" is the issue number)
• It's been tested on a Cordova (iOS, Android) app
• It's been tested on an Electron app
• Any necessary documentation has been added or updated in the docs or explained in the PR's description.

If adding a new feature, the PR's description includes:

• A convincing reason for adding this feature (to avoid wasting your time, it's best to start a new feature discussion first and wait for approval before working on it)

Other information:

For a while, in the Vue ecosystem we've been augmenting @vue/runtime-core to add custom properties and more to vue. However, this inadvertently breaks the types for projects that augment vue - which is (now?) the officially recommended in the docs way to augment these interfaces (for example, ComponentCustomProperties, GlobalComponents and so on).

This means all libraries must update their code (or it will break the types of the libraries that augment vue instead).

Here's an example of how the augmented types end up broken.

This PR is a small effort to ensure the ecosystem is consistent. For context, you can see that vue-router has moved to do this, as well as Nuxt.

[yusufkandemir]

Thanks for noticing this and submitting a PR 👏

We've addressed this for the components we were providing in
4897920. We are augmenting them all to ensure full coverage. But, we've overlooked the other parts such as example code, scaffolded code, etc. So, now everything should be fine.

[yusufkandemir]

The fix will be available in the next releases of @quasar/app-vite(beta), @quasar/app-webpack(beta), create-quasar, and the next deployment of the docs.

We should backport the changes to app-vite and app-webpack to stable releases as well.