feat: add UpdateStore

[andreadistefano]

Description

Hi! I added a RenameStore request in order to implement the same feature in OpenFGA, which I'm working on. This is my first time using protocol buffers so I hope everything is right.

References

This issue.

Review Checklist

• [x] I have clicked on "allow edits by maintainers".
• [x] I have added documentation for new/changed functionality in this PR or in a PR to openfga.dev [Provide a link to any relevant PRs in the references section above]
• [x] The correct base branch is being used, if not main
• [ ] I have added tests to validate that the change in functionality is working as expected

[linux-foundation-easycla[bot]]

The committers listed above are authorized under a signed CLA.

• :white_check_mark: login: andreadistefano / name: Andrea Di Stefano (ac1234491a401c92d218c8edd387f6ad859aa89a, 47fb8843d5072ec4baf4c795d02559e3728c5080, c94e9071f34bf106bc14efd688196c6725f14157)

[andreadistefano]

Thanks for the contribution Andrea!

Thank you all for your help and your patience! This is all new to me and I've learned a lot, but there's still a lot more