Add test tsconfigs in eslint projects

[charisk]

Moving the VS Code integration tests (#1912) without adding the project to the eslint config meant that we'd get the following error when running npm run format-staged:

ql-vscode/test/vscode-tests/minimal-workspace/databases/db-panel.test.ts
  0:0  error  Parsing error: "parserOptions.project" has been set for @typescript-eslint/parser.
The file does not match your project config: test/vscode-tests/minimal-workspace/databases/db-panel.test.ts.
The file must be included in at least one of the projects provided

Checklist

N/A:

• CHANGELOG.md has been updated to incorporate all user visible changes made by this pull request.
• Issues have been created for any UI or other user-facing changes made by this pull request.
• [Maintainers only] If this pull request makes user-facing changes that require documentation changes, open a corresponding docs pull request in the github/codeql repo and add the ready-for-doc-review label there.