feat: upload CLI artifacts to external storage (#84)

Description

Upload CLI artifacts to external storage:

• create a GCP_SERVICE_KEY
• upload CLI binaries to GCP Buckets
• improve make commands
• add new target architectures

Related issue

#84 (closed)

Examples

https://storage.cloud.google.com/database-lab-cli/0.0.1/dblab-darwin-386

https://storage.cloud.google.com/database-lab-cli/latest/dblab-darwin-386

curl https://gitlab.com/postgres-ai/database-lab/-/raw/84-external-artifact-storage/scripts/cli_install.sh | bash
sudo mv ~/.dblab/dblab /usr/local/bin/dblab

TODO

• fix the link in the installation script
• support macos (darwin)

Checklist

• the MR description has been reviewed
• this MR contains text changes and they have been reviewed OR there are no texts changes
• this MR contains GUI/CLI changes and they have been reviewed OR there are no GUI/CLI changes
• this MR contains API changes, specifications reflect those changes and they have been reviewed OR there are no API changes

Closes #84 (closed)