Feature Request: Support Optional Schema creates as config

[hanseltime]

For an org that would like to keep tighter permissions and declarative schemas in their databases, SQLMesh's migrate and plan fails if they don't have Schema create permissions. This is a rather large surface area to give to a tool that, even for Virtual Data Environments, needs to have that it.

In response to this discussion, I have currently overridden the Enginer Adapters to skip schema creation: #4016

However, this feels like a pretty obvious large scale need that would benefit from first class support in the config.

My proposal is to add some sort of db flag or config option like create_schemas: false. When that happens, then we switch off the create_schema logic to simply log "skipping schema creation {schema} due to create_schemas: false`.