feat(postprocessor): integrate OwlBot locally and add basic post-processor to copy generated code into libraries

[adrianajg]

Create .github/.OwlBot.yaml and .github/.OwlBot.lock.yaml files

• Invoking OwlBot locally copies generated code into specified destination directory: owl-bot-staging/

Create basic post-processor

• Invoking post-processor locally copies code from owl-bot-staging/ into respective libraries and performs go mod tidy and gofmt -sdwl . on each directory

[codyoss]

Overall looks just, just a handful of small cleanup stuff.

[codyoss]

Just a couple more small things

[codyoss]

It looks like you still have these files checked in. An easy way to fix is comment out line in gitignore, delete them temp, uncomment gitignore, readded them for yourself locally.

[adrianajg]

I can't tell -- does it look like I fixed it?

[codyoss]

LGTM, thanks