feat(genai): Sample/textgen part1 #4160

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@Guiners

The following contributors were found for this pull request:

✅ eaa09e7 Author: @Guiners <50328216+Guiners@users.noreply.github.com>
✅ 6729ca7 Author: <r***a@softserveinc.com>
✅ 2e9fb52 Co-Author: <sam******mar@gmail.com>
✅ 6b9003a Author: @msampathkumar <sa****hm@google.com>
✅ 6dd92f9 Author: @gericdong <it****c@google.com>

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