Add stdout support for meas command

[ubombar]

Description

This PR adds support for the -o / --stdout flag in the meas subcommand. While the flag was previously implemented, its functionality was missing. This update ensures that the output can be written directly to stdout.

Changes

• Added a boolean variable useStandardOut to the function getMeasMdFile for determining where to output the result.
• When useStandardOut is true, the function prints the JSON output to os.Stdout.
• The function now returns "" (empry string) instead of a filename when the flag is set and an error occurs.

Testing

• Manually tested the new functionality by running commands and verifying output behavior.
• No issues were observed during manual testing.
• Unit tests are not yet implemented but should be added in the future.

Backward Compatibility

• These changes are non-breaking and do not affect existing functionality.