[TRI-1125] `@trigger.dev/cli init` reports the wrong file name for app dir and javascript projects

[ericallam]

I just ran @trigger.dev/cli init against a Next.js project using the App Dir and JavaScript and it output the following message:

✅ Created app route at src/app/api/trigger.ts

Even though the file was actually created at src/app/api/trigger/route.js

We should make sure that this output is correctly specified for different setups:

• App Dir w/ JS
• App Dir w/ TS
• Pages Dir w/ JS
• Pages Dir w/ TS

_TRI-1125

[Chigala]

I'll look into this