feat: add --config-name argument to allow multiple configs

[GuillaumeLagrange]

Allows using the codspeed CLI in different environments without having to re-log in everytime

Helpful bindings to go along

        eval $(op signin)
        export CODSPEED_CONFIG_NAME=dev
        export CODSPEED_API_URL=$(op read "op://Private/codspeed_urls/dev_api_url")
        export CODSPEED_UPLOAD_URL=$(op read "op://Private/codspeed_urls/dev_upload_url")