#156 `graphweaver init` UX improvements

[Anonymous]

Originally created by: kyelewis

https://github.com/exogee-technology/graphweaver/issues/153

• Update printing of CLI arguments for init and import
• Remove currently unused init arguments
• Default name and backends in the interactive flow if one is provided on CLI
• Allow specifying multiple backends on CLI
• Validate project name
• Update instructions to include to change to the project directory.
• Return error code 1 if there are missing packages on import