fix(cli): improve no stacks found message in synth output

[nithishravindra]

Related issue

Fixes #2793

Description

Updates the error message shown when no stacks are found during cdktf synth to be more descriptive. This helps users understand they need to define at least one TerraformStack in their CDKTF application

Checklist

• I have updated the PR title to match CDKTF's style guide
• I have run the linter on my code locally
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation if applicable
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works if applicable
• New and existing unit tests pass locally with my changes

[hashicorp-cla-app]

All committers have signed the CLA.

[ansgarm]

Looks good to me, @nithishravindra 👍

[ansgarm]

I think I'd refer to a specific configuration (i.e. the one at hand) and therefore add a "the" to make that more specific. But that's mostly my personal choice, and I'd be open to skip this or get some feedback from a native speaker :)

Suggested change

	: "No stacks found in configuration."}
	: "No stacks found in the configuration."}

[mutahhir]

I think the existing one is slightly better, but also just a personal choice. Non-native speaker

[ansgarm]

(if we change the wording, this needs an update as well)

Suggested change

	expect(stripAnsi(lastFrame())).toBe("No stacks found in configuration.");
	expect(stripAnsi(lastFrame())).toBe("No stacks found in the configuration.");

[mutahhir]

Minor nits, but overall good to go! Thank you for adding tests for this too!

[mutahhir]

I think the existing one is slightly better, but also just a personal choice. Non-native speaker

[mutahhir]

I'd rather this be split into two tests. While it is completely fine, I'm personally not a big fan of restricting scope like this. That being said, if you want there to be just one test, you can use let instead of const. We do that a lot where we want to test a variety of small changes within the same test.