[DLP] Implemented samples for inspect on datastore, gcs and bigquery data and send results to SCC (#10289)

## Description
This PR includes 3 samples for inspecting data and send results to SCC and their tests are implemented using **mocking approach**:

1. [inspect_datastore_send_to_scc](https://cloud.google.com/dlp/docs/sending-results-to-scc.md?g=0&l=416#datastore-data)
2. [inspect_gcs_send_to_scc](https://cloud.google.com/dlp/docs/sending-results-to-scc.md?g=0&l=416#cloud-storage-data)
3. [inspect_bigquery_send_to_scc](https://cloud.google.com/dlp/docs/sending-results-to-scc.md?g=0&l=416#bigquery-data)

Fixes #<ISSUE-NUMBER>

Note: Before submitting a pull request, please open an issue for discussion if you are not associated with Google.

## Checklist
- [x] I have followed [Sample Guidelines from AUTHORING_GUIDE.MD](https://github.com/GoogleCloudPlatform/python-docs-samples/blob/main/AUTHORING_GUIDE.md)
- [ ] README is updated to include [all relevant information](https://github.com/GoogleCloudPlatform/python-docs-samples/blob/main/AUTHORING_GUIDE.md#readme-file)
- [x] **Tests** pass:   `nox -s py-3.9` (see [Test Environment Setup](https://github.com/GoogleCloudPlatform/python-docs-samples/blob/main/AUTHORING_GUIDE.md#test-environment-setup))
- [x] **Lint** pass:   `nox -s lint` (see [Test Environment Setup](https://github.com/GoogleCloudPlatform/python-docs-samples/blob/main/AUTHORING_GUIDE.md#test-environment-setup))
- [ ] These samples need a new **API enabled** in testing projects to pass (let us know which ones)
- [ ] These samples need a new/updated **env vars** in testing projects set to pass (let us know which ones)
- [ ] This sample adds a new sample directory, and I updated the [CODEOWNERS file](https://github.com/GoogleCloudPlatform/python-docs-samples/blob/main/.github/CODEOWNERS) with the codeowners for this sample
- [ ] This sample adds a new **Product API**, and I updated the [Blunderbuss issue/PR auto-assigner](https://github.com/GoogleCloudPlatform/python-docs-samples/blob/main/.github/blunderbuss.yml) with the codeowners for this sample
- [x] Please **merge** this PR for me once it is approved

Author: Avani-Thakker-Crest