feat(env): add detection for workspace ID

[anthony-gomez-fastly]

Change summary

Allow for future commands to add an optional -workspace-id flag that will check for FASTLY_WORKSPACE_ID in env vars if no value is supplied

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[rcaril]

LGTM - did we need to test this locally?

[anthony-gomez-fastly]

@rcaril I modified an existing function to accept the flag, and was able to print the string provided. however i also noticed some default vals that would be useful so added them as well