feat: add name to workspace agent devcontainers (#17089)

In the presence of multiple devcontainers, it would be nice to
differentiate them by name. This change inherits the resource name from
terraform.

Refs #17076

coderd/database/migrations/000309_add_devcontainer_name.up.sql

@@ -0,0 +1,4 @@
+ALTER TABLE workspace_agent_devcontainers ADD COLUMN name TEXT NOT NULL DEFAULT '';
+ALTER TABLE workspace_agent_devcontainers ALTER COLUMN name DROP DEFAULT;
+
+COMMENT ON COLUMN workspace_agent_devcontainers.name IS 'The name of the Dev Container.';