Amends c45fc76944f8a280ccc9483cc47236fd98275fb6

* Update github actions
* Update ci-scripts
* Remove unused test folder
* Remove unused dependencies & update `ThirdPartyNotices.txt`s
* Remove unused activation events

Fixes: VSCODEEXT-79
Fixes: VSCODEEXT-80
Change-Id: I450fefdde5209454ef11e1b9cd12162753d4fa36
Reviewed-by: Marcus Tillmanns <marcus.tillmanns@qt.io>

Change-Id: I272fb5f3b8ffe2e1dcd1cbe7a339de9a34b0a7ad
Reviewed-by: Marcus Tillmanns <marcus.tillmanns@qt.io>

The below Extensions are created with this commit:

* qt-core
* qt-official
* qt-ui

qt-core

This extension is the core extension for the Qt extensions.
It provides the basic functionalities for the other extensions to work.

* It handles the communication between the other extensions.
* It provides the basic functionalities and common features for the other extensions.
* The all other extensions depend on this extension.

qt-ui

This extension provides the UI functionalities.

* It communicates with the `qt-core` extension to get information about the Qt Widget Designer.
* It provides syntax highlighting for `.ui` files.

qt-official

This extension has the rest of the previous monolithic extension functionalities.
It should be divided into more extensions in the future.

This commit implements:

* Common functionalities are moved from `qt-official` to `qt-core`.
* `qt-lib` is implemented as a npm module to gather the common code.
* Static analysis tools for every extension are added.
* Updated all `package.json` files to reflect the changes.
* `ci-scripts` is implemented to run the static analysis tools and tests.
* The `common` is created to gather the common code for tools.
* Extension packs are updated.
* The `ThirdPartyNotices.txt` files are generated for every extension.
* The `README.md` files are updated to reflect the changes.
* `.vscode/launch.json`, `.vscode/extensions.json`, and `.vscode/tasks.json` are updated.

Change-Id: Iac9b7e071275e92cdfbb3a47fba24d3ba8e41c89
Reviewed-by: Marcus Tillmanns <marcus.tillmanns@qt.io>
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>

* Disable unit tests for a while
* Add `ci-lint` for ci tasks because `lint` has `prettier --write` and
`eslint . --fix` which try to fix problems but they are useless on CI.
Use `prettier -c` and normal `eslint` instead to show errors so that
developers fix them in their branches.

Change-Id: I9d9098dfe82dfacad9b1bad68581b26b1ccc2c49
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>

The artifact is available as 'vsix_package'.

Change-Id: Ief79c9b38d8d12931b9ee43031fb3d522e829b31
Reviewed-by: Marcus Tillmanns <marcus.tillmanns@qt.io>

...instead of relying on coactions/setup-xvfb that was triggering
deprecation warnings.

Change-Id: Ib2d2d48ba9a3318ff795e40bb8872c9a6cf72b6c
Reviewed-by: Marcus Tillmanns <marcus.tillmanns@qt.io>

For starters, just build on Linux.

Change-Id: I133a0de37adfc05078c834d2130f17b2dc864106
Reviewed-by: Marcus Tillmanns <marcus.tillmanns@qt.io>

* Add CONTRIBUTING.md
* Add .github/pull_request_template.md

Change-Id: I37e9fb607096ed9efb8e2b590be0357b7051f165
Reviewed-by: Kai Köhne <kai.koehne@qt.io>
Reviewed-by: Marcus Tillmanns <marcus.tillmanns@qt.io>