Consider remove bendctl

[BohuTANG]

bendctl is no used now, and we recommend that use our guideline to deploy Databend:
https://databend.rs/doc/category/deploy

We need redesign the new bendctl in the future to meet the needs of on-perm deployment.

cc @ZhiHanZ

[sundy-li]

I think we can upgrade bendctl to bendsql or bend-cli as snowsql

[BohuTANG]

Hello @sundy-li ,

snowsql is not a deploy tool, for now we just need to provide a deployment tool for the community user easy to use.

[PsiACE]

I think we can keep just a basic version management and deployment tool. It looks like nvm does.

Also, we can design it like cargo to make it easy for others to load their own custom subcommands.

[ZhiHanZ]

I think the main challenge for current bendctl is the pressure from maintainence. Further adoption would be focused on on-prem k8s cluster deployment or interact with cloud warehouses. For local environment, mainly used for test and demo purpose, we could depreciate it for now