Prompt user if Terraform utilised for deploying infrastructure (#1004)

## Changes
Added prompt is_terraform_used and updated the same in the config of
WorkspaceInstaller

Resolves #393

---------

Co-authored-by: Serge Smertin <259697+nfx@users.noreply.github.com>

src/databricks/labs/ucx/config.py

@@ -37,6 +37,9 @@ class WorkspaceConfig:  # pylint: disable=too-many-instance-attributes
     policy_id: str | None = None
     num_days_submit_runs_history: int = 30
 
+    # Flag to see if terraform has been used for deploying certain entities
+    is_terraform_used: bool = False
+
     def replace_inventory_variable(self, text: str) -> str:
         return text.replace("$inventory", f"hive_metastore.{self.inventory_database}")
 

src/databricks/labs/ucx/install.py

@@ -244,6 +244,9 @@ def warehouse_type(_):
                 instance_profile, spark_conf_dict = self._get_ext_hms_conf_from_policy(cluster_policy)
 
         policy_id = self._create_cluster_policy(inventory_database, spark_conf_dict, instance_profile)
+
+        # Check if terraform is being used
+        is_terraform_used = self._prompts.confirm("Do you use Terraform to deploy your infrastructure?")
         config = WorkspaceConfig(
             inventory_database=inventory_database,
             workspace_group_regex=configure_groups.workspace_group_regex,
@@ -258,6 +261,7 @@ def warehouse_type(_):
             instance_profile=instance_profile,
             spark_conf=spark_conf_dict,
             policy_id=policy_id,
+            is_terraform_used=is_terraform_used,
         )
         self._installation.save(config)
         ws_file_url = self._installation.workspace_link(config.__file__)