Use schema field for pipeline in builtin template (#2347)

## Changes

The `schema` field implies the lifecycle of tables is no longer tied to
the lifecycle of the pipeline, as was the case with the `target` field.

More information about using the "catalog" and "schema" properties can
be found here:
https://docs.databricks.com/en/delta-live-tables/target-schema.html

## Tests

n/a

---------

Co-authored-by: Lennart Kats (databricks) <lennart.kats@databricks.com>

acceptance/bundle/templates/default-python/classic/out.compare-vs-serverless.diff

@@ -48,7 +48,7 @@
 -      catalog: main
 +      ## Specify the 'catalog' field to configure this pipeline to make use of Unity Catalog:
 +      # catalog: catalog_name
-       target: my_default_python_${bundle.target}
+       schema: my_default_python_${bundle.target}
 -      serverless: true
        libraries:
          - notebook:

acceptance/bundle/templates/default-python/classic/output/my_default_python/resources/my_default_python.pipeline.yml

@@ -5,7 +5,7 @@ resources:
       name: my_default_python_pipeline
       ## Specify the 'catalog' field to configure this pipeline to make use of Unity Catalog:
       # catalog: catalog_name
-      target: my_default_python_${bundle.target}
+      schema: my_default_python_${bundle.target}
       libraries:
         - notebook:
             path: ../src/dlt_pipeline.ipynb

acceptance/bundle/templates/default-python/serverless-customcatalog/output.txt

@@ -18,5 +18,5 @@ See also the documentation at https://docs.databricks.com/dev-tools/bundles/inde
 -      ## Catalog is required for serverless compute
 -      catalog: main
 +      catalog: customcatalog
-       target: my_default_python_${bundle.target}
+       schema: my_default_python_${bundle.target}
        serverless: true

acceptance/bundle/templates/default-python/serverless/output/my_default_python/resources/my_default_python.pipeline.yml

@@ -5,7 +5,7 @@ resources:
       name: my_default_python_pipeline
       ## Catalog is required for serverless compute
       catalog: main
-      target: my_default_python_${bundle.target}
+      schema: my_default_python_${bundle.target}
       serverless: true
       libraries:
         - notebook:

integration/bundle/testdata/default_python/bundle_summary.txt

@@ -164,7 +164,7 @@
           }
         ],
         "name": "[dev [USERNAME]] project_name_$UNIQUE_PRJ_pipeline",
-        "target": "project_name_$UNIQUE_PRJ_dev",
+        "schema": "project_name_$UNIQUE_PRJ_dev",
         "url": "[DATABRICKS_URL]/pipelines/[UUID]?o=[NUMID]"
       }
     }

libs/template/templates/default-python/template/{{.project_name}}/resources/{{.project_name}}.pipeline.yml.tmpl

@@ -13,7 +13,7 @@ resources:
       {{- else}}
       catalog: {{default_catalog}}
       {{- end}}
-      target: {{.project_name}}_${bundle.target}
+      schema: {{.project_name}}_${bundle.target}
       {{- if $with_serverless }}
       serverless: true
       {{- end}}