Fix TS support for Vue3 branch and add configuration for the codebase TS migration

[IlCallo]

What kind of change does this PR introduce? (check at least one)

• Bugfix
• Feature
• Documentation
• Code style update
• Refactor
• Build-related changes
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Does this PR introduce a breaking change? (check one)

• Yes
• No

If yes, please describe the impact and migration path for existing applications:

The PR fulfills these requirements:

• It's submitted to the dev branch and not the master 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 a Electron app
• Any necessary documentation has been added or updated in the docs (for faster update click on "Suggest an edit on GitHub" at bottom of page) 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 open a suggestion issue first and wait for approval before working on it)

Other information:
Currently the TS rollup plugin will complain when yarn build is run as it doesn't find any TS file, but it finishes the build successfully.

I removed fork-ts-checker version management as v4 doesn't support Vue3 anyway, so we must use v5+
At least in v6 (currently in alpha, I updated to v5 in the meantime) there should be some kind of integrated performance tracker to identify where is the edge case problem I discovered last time I tried the upgrade

Before releasing Quasar 2 it's vital to convert at least 2-3 components/mixins/directives/plugin to composition-api + TS to spot edge cases which would require breaking changes, otherwise we could end up "wasting" a major release.
I already did it with a component and mixin on yusuf test repo and documented the procedure, I can port the changes and convert some more when this PR is merged