fix: Make CDKTF_LOG_FILE_DIRECTORY a common flag available on all c…

…ommands (#3495)

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### Related issue

Fixes #3489 

### Description

We were using `CDKTF_LOG_FILE_DIRECTORY` within our logger, but we never
made it into a supported CLI flag. CDKTF configures
[yargs](https://yargs.js.org/) in a way that all environment variables
with the `CDKTF_` prefix are treated as CLI flags. For commands that had
[`strict`](https://yargs.js.org/docs/#api-reference-strictenabledtrue)
enabled, that means that setting any non-supported flag with the
`CDKTF_` prefix would cause the command to fail. This PR now adds
support for this flag and it should work across all commands.

---------

Co-authored-by: Ansgar Mertens <ansgar@hashicorp.com>

packages/cdktf-cli/src/bin/cdktf.ts

@@ -111,6 +111,10 @@ yargs
     required: false,
     desc: "Which log level should be written. Only supported via setting the env CDKTF_LOG_LEVEL",
   })
+  .option("log-file-directory", {
+    require: false,
+    desc: "The directory path where CDKTF should create `cdktf.log` and print logs at the `debug` level. If not set, CDKTF writes logs to standard out at the level specified in `CDKTF_LOG_LEVEL`. Only supported via setting the env CDKTF_LOG_FILE_DIRECTORY",
+  })
   .option("context-json", {
     required: false,
     hidden: true,