feat: microgen - adds config file (#2284)

* chore: removes old proof of concept

* removes old __init__.py

* Adds two utility files to handle basic tasks

* Adds a configuration file for the microgenerator

* Removes unused comment

Author: chalmerlowe

scripts/microgenerator/config.yaml

@@ -0,0 +1,74 @@
+# config.yaml
+
+# The name of the service, used for variable names and comments.
+service_name: "bigquery"
+
+# A list of paths to the source code files to be parsed.
+# Globs are supported.
+source_files:
+  services:
+    - "google/cloud/bigquery_v2/services/dataset_service/client.py"
+    - "google/cloud/bigquery_v2/services/job_service/client.py"
+    - "google/cloud/bigquery_v2/services/model_service/client.py"
+    - "google/cloud/bigquery_v2/services/project_service/client.py"
+    - "google/cloud/bigquery_v2/services/routine_service/client.py"
+    - "google/cloud/bigquery_v2/services/row_access_policy_service/client.py"
+    - "google/cloud/bigquery_v2/services/table_service/client.py"
+  types:
+    - "google/cloud/bigquery_v2/types/dataset.py"
+    - "google/cloud/bigquery_v2/types/job.py"
+    - "google/cloud/bigquery_v2/types/model.py"
+    - "google/cloud/bigquery_v2/types/project.py"
+    - "google/cloud/bigquery_v2/types/routine.py"
+    - "google/cloud/bigquery_v2/types/row_access_policy.py"
+    - "google/cloud/bigquery_v2/types/table.py"
+
+
+# Filtering rules for classes and methods.
+filter:
+  classes:
+    # Only include classes with these suffixes.
+    include_suffixes:
+      - "ServiceClient"
+      - "Request"
+    # Exclude classes with these suffixes.
+    exclude_suffixes:
+      - "BigQueryClient"
+  methods:
+    # Include methods with these prefixes.
+    include_prefixes:
+      - "batch_delete_"
+      - "cancel_"
+      - "create_"
+      - "delete_"
+      - "get_"
+      - "insert_"
+      - "list_"
+      - "patch_"
+      - "undelete_"
+      - "update_"
+    # Exclude methods with these prefixes.
+    exclude_prefixes:
+      - "get_mtls_endpoint_and_cert_source"
+    overrides:
+      patch_table:
+        request_class_name: "UpdateOrPatchTableRequest"
+      patch_dataset:
+        request_class_name: "UpdateOrPatchDatasetRequest"
+
+# A list of templates to render and their corresponding output files.
+templates:
+  - template: "templates/client.py.j2"
+    output: "google/cloud/bigquery_v2/services/centralized_service/client.py"
+  - template: "templates/_helpers.py.j2"
+    output: "google/cloud/bigquery_v2/services/centralized_service/_helpers.py"
+  - template: "templates/__init__.py.j2"
+    output: "google/cloud/bigquery_v2/services/centralized_service/__init__.py"
+
+post_processing_templates:
+  - template: "templates/post-processing/init.py.j2"
+    target_file: "google/cloud/bigquery_v2/__init__.py"
+    add_imports:
+      - "from .services.centralized_service import BigQueryClient"
+    add_to_all:
+      - "BigQueryClient"