CLI Error Messages are Inaccurate with regards to flags usage

[raahmed]

Context: Running Python on Functions in Linux (Preview) on VS Code.

Severity: Potentially Serious (Potentially Blocking)

Reproduction Steps:

1. CLI error messages are inaccurate and confusing - notice how the --name flag is present in the command.

Mitigation Method:

1. Have accurate error messages that point, specifically, to the actual problem.
   Note: In this case, the actual error was never found. While debugging this issue, I encountered other issues that, once fixed, eventually led to this error never being seen again.

[asavaritayal]

This issue was moved to Azure/azure-functions-core-tools#955