feat(bigqueryv2): Add Big Query v2 client libraries/ samples

[vijaykanthm]

Description

Reference to https://b.corp.google.com/issues/339692211 This PR adds v2 API Big Query Go client samples to Create, List, Get, Delete & Update.

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

Checklist

• [ ] I have followed Contributing Guidelines from CONTRIBUTING.MD
• [ ] Tests pass: go test -v ./.. (see Testing)
• [ ] Code formatted: gofmt (see Formatting)
• [ ] Vetting pass: go vet (see Formatting)
• [ ] 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 with the codeowners for this sample
• [ ] This sample adds a new Product API, and I updated the Blunderbuss issue/PR auto-assigner with the codeowners for this sample
• [ ] Please merge this PR for me once it is approved

[conventional-commit-lint-gcf[bot]]

🤖 I detect that the PR title and the commit message differ and there's only one commit. To use the PR title for the commit history, you can use Github's automerge feature with squashing, or use automerge label. Good luck human!

-- conventional-commit-lint bot https://conventionalcommits.org/

[snippet-bot[bot]]

Here is the summary of changes.

You are about to add 5 region tags.

• securitycenter/bigqueryv2/create_big_query_export.go:17, tag securitycenter_create_big_query_export_v2
• securitycenter/bigqueryv2/delete_big_query_export.go:17, tag securitycenter_delete_big_query_export_v2
• securitycenter/bigqueryv2/get_big_query_export.go:17, tag securitycenter_get_big_query_export_v2
• securitycenter/bigqueryv2/list_big_query_export.go:17, tag securitycenter_list_big_query_export_v2
• securitycenter/bigqueryv2/update_big_query_export.go:17, tag securitycenter_update_big_query_export_v2

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[vijaykanthm]

I just realized: is this PR a duplicate of #4272 ?

That will be closed, it is not being worked on currently. I have discussed with the requester and taken over the work.