fix the allow_empty_target OU path issue

[danxie1999]

Why?

When I enable the allow_empty_target parameter in the adfconfig.yml file, if I set a target OU path which does not exist in my AWS organization, I will get following error.

{
  "errorMessage": "Path /TenantXXX/Shared failed to return a child OU at 'TenantXXX'",
  "errorType": "ValueError",
  "requestId": "d786ed75-3ce9-4995-a7b6-75fa40454c86",
  "stackTrace": [
    "  File \"/var/task/generate_pipeline_inputs.py\", line 223, in lambda_handler\n    pipeline_input_data = generate_pipeline_inputs(\n",
    "  File \"/var/task/generate_pipeline_inputs.py\", line 151, in generate_pipeline_inputs\n    pipeline_target.fetch_accounts_for_target()\n",
    "  File \"/opt/python/target.py\", line 319, in fetch_accounts_for_target\n    self._target_is_ou_path(\n",
    "  File \"/opt/python/target.py\", line 260, in _target_is_ou_path\n    responses = self.organizations.get_accounts_in_path(\n",
    "  File \"/opt/python/organizations.py\", line 384, in get_accounts_in_path\n    ou_id = self.ou_path_to_id(path) if not ou_id else ou_id\n",
    "  File \"/opt/python/organizations.py\", line 367, in ou_path_to_id\n    raise ValueError(\n"
  ]
}

My deployment map file look like below:

pipelines:
  - name: platform-demo-empty-target
    description: |-
      Deploys Demo Stack to test ADF features
    default_providers:
      source:
        provider: codecommit
      build:
        provider: codebuild
    params:
      restart_execution_on_update: True
    targets:
      - name: Deploy-Non-Exist-Ou-Path
        path: /TenantXXX/Shared
        properties:
          template_filename: DemoStack1.template

What?

The reason of above error is that the src/lambda_codebase/initial_commit/bootstrap_repository/adf-build/shared/python/target.py only capture the boto3 Client Error and ignore the Error raised in the method get_accounts_in_path in orgnizations.py. So, an easy fix is to change the boto3 Client Error to Exception and ignore it if the allow_empty_target was enabled.

[sbkok]

I don't think we should broaden the except type, as this would imply unrelated exceptions (think network or auth errors) would be hidden if adf_deployment_maps_allow_empty_target is set to true.

Could you please revert this change, then add support for another except that handles the error that it throws?