* feat: adding proto autogenerated code changes for proto column feature

* feat: add implementation for Proto columns DDL

* feat: add implementation for Proto columns DML

* feat: add implementation for Proto columns DQL

* feat: add NoneType check during Proto deserialization

* feat: add code changes for Proto DDL support

* feat: add required proto files to execute samples and tests

* feat: add sample snippets for Proto columns DDL

* feat: add tests for proto columns ddl, dml, dql snippets

* feat: code refactoring

* feat: remove staging endpoint from snippets.py

* feat: comment refactor

* feat: add license file

* feat: update proto column data in insertion sample

* feat: move column_info argument to the end to avoid breaking code

* feat: add integration tests for Proto Columns

* feat: add unit tests for Proto Columns

* feat: update tests to add column_info argument at end

* feat: remove deepcopy during deserialization of proto message

* feat: tests refactoring

* feat: integration tests refactoring

* feat: samples and sample tests refactoring

* feat: lint tests folder

* feat:lint samples directory

* feat: stop running emulator with proto ddl commands

* feat: close the file after reading

* feat: update protobuf version lower bound to >3.20 to check proto message compatibility

* feat: update setup for snippets_tests.py file

* feat: add integration tests

* feat: remove duplicate integration tests

* feat: add proto_descriptor parameter to required tests

* feat: add compatibility tests between Proto message, Bytes and Proto Enum, Int64

* feat: add index tests for proto columns

* feat: replace duplicates with sample data

* feat: update protobuf lower bound version in setup.py file to add support for proto messages and enum

* feat: lint fixes

* feat: lint fix

* feat: tests refactoring

* feat: change comment from dml to dql for read

* feat: tests refactoring for update db operation

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md