feat(cli): --ext parameter for run, compile, and bundle

[Cre3per]

Adds --ext to deno run, closes #5088

Additionally

• Adds --ext to deno compile and deno bundle
• Deprecates deno eval --ts (Was already marked for removal in code, this PR exposes the deprecation to the CLI)
• ⚠️ Changes the default value of deno fmt --ext from ts to js for consistency. If CLI default arguments are part of deno's API, this violates semver and needs to be undone. Personally, I'd prefer TypeScript to be the default for all commands, but JavaScript was chosen here Request: CLI flag to set language mode #5088 (comment). Changing the default value to TypeScript would not avoid the breaking change, because the main branch is inconsistent already (fmt vs eval).

You'll find a new TODO concerning deno_ast in the changes. I intend to address that TODO before this PR is merged, after I get confirmation that the PR is otherwise ok.

[kt3k]

Is it correct for #17269 to close this? @dsherret

[dsherret]

Only if it increases my closed issue count.

[dsherret]

Thanks and sorry, this was done in error. I meant to close #17112, when I copy and pasted the issue number gh did some auto complete weirdness that must have selected this one.

[aapoalas]

Please resolve conflicts.

For what it's worth, the changes themselves seem fine to me. Consistency is good, and the breaking change here is very minor since it only affects pipe operation and extensionless input files. As such, I'd be willing to "look the other way" in terms of breaking semver. I do not decide that though.

[dsherret]

Looks a lot better! Thanks! I have just a few comments.

[dsherret]

LGTM. Thanks @Cre3per!

[Cre3per]

I had a look at your commits, looks good. Thanks for your feedback @dsherret!

[dsherret]

@Cre3per and sorry for my delay on this one! I did a few commits just now because I want to get this in the release (happening in a little bit).

[kt3k]

Now deno run - seems handling the stdin as JavaScript by default:

$ echo "console.log(1 as any)" | deno run  -        
error: The module's source code could not be parsed: Expected ',', got 'as' at file:https:///Users/kt3k/denoland/deno_std/$deno$stdin:1:15

  console.log(1 as any)
                ~~
$ echo "console.log(1 as any)" | deno run --ext ts -
1
$ deno -V
deno 1.32.0

Is this expected? (Some test cases in std failed by this change)

[Cre3per]

@kt3k That's unintentional. I'm adding a test case for deno run - and working on a fix.

UPDATE: Fixed in #18391