Open for discussion if this is something we want to support. The alternative is #9715 where we disable ts support altogether in non-ts projects.

If we opt to use #9715 instead, it needs a few adjustments to remove .ts files from the resolve rules etc.

PR Checklist

• The PR title follows our guidelines: https://github.com/NativeScript/NativeScript/blob/master/tools/notes/CONTRIBUTING.md#commit-messages.
• There is an issue for the bug/feature this PR is for. To avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it.
• You have signed the CLA.
• All existing tests are passing: https://github.com/NativeScript/NativeScript/blob/master/tools/notes/DevelopmentWorkflow.md#running-unit-tests-application.
• Tests for the changes are included - https://github.com/NativeScript/NativeScript/blob/master/tools/notes/WritingUnitTests.md.

What is the current behavior?

Using .ts file in non-ts projects throw errors (as expected at the moment)

What is the new behavior?

If the project does not have a tsconfig.json a default one is used from @nativescript/webpack. The user is still required to install typescript to use ts files.

fixes #9715