Version 3.0.0 alpha 2

• Add web-ui v3.0.0a2
• Upgrade FastAPI to v0.82.0
• API endpoint to get the locked status of a project
• Global project lock and unlock
• Update appliance files
• Require name for custom adapters. Fixes #2098
• Allow empty adapter slots for Dynamips templates. Ref GNS3/gns3-gui#3373
• Use original $PATH in init.sh for Docker containers. Ref #2069