Import types instead of import and prepare update to TS5.0

[gfontorbe]

Closes #960

• Prepare upgrade to TypeScript 5.0.x
• Adds new linter rule to use import type instead of import for imports that are only used for types and not values
• Fixed linter issues for the new rule
• Adapted langium-cli and generators to reflect those changes
• Some styling here and there

[dhuebner]

Please remove the test project from the package-lock. Also check that clean-up step is inside a finally block

[gfontorbe]

Please remove the test project from the package-lock. Also check that clean-up step is inside a finally block

The clean-up step is already in a finally block, not sure why this was added to the package-lock...

[dhuebner]

Please remove the test project from the package-lock. Also check that clean-up step is inside a finally block

The clean-up step is already in a finally block, not sure why this was added to the package-lock...

Do you have this folder locally? Maybe it is there since you was adding new CLI tests?

[dhuebner]

@gfontorbe
It is really difficult to track all the changes.
Just hope we have enough tests and enough time to find potential bugs :)
Would be nice if someone else could also look through.

[msujew]

It isn't noticeable since the ast.ts files get generated with an eslint-disable instruction, but these files aren't using the import type statements correctly:

import type { AstNode, Reference, ReferenceInfo, TypeMetaData } from 'langium';
import { AbstractAstReflection } from 'langium';

We currently only generate

import { AstNode, AbstractAstReflection, Reference, ReferenceInfo, TypeMetaData } from 'langium';

[msujew]

Looks good, please rebase on top of the latest main and merge at the end of the week as discussed 👍