Version: Introduce products

What

Fixes #7056 (closed)

This merge request introduces products to octez-version.

For now, Only Octez product is added and parsed. More products will come afterwards.

Why

Preliminary work to having specific releases for products, such as Etherlink.

How

• Updates the version parser
• Adds a --product argument to print_version
• Updates encoding
• Renames tezos_print_version to octez_print_version

Manually testing the MR

• Run dune exec src/lib_version/exe/octez_print_version.exe
• Check the version
• Create a tag "octez-v1234.4321`
• Run again dune exec src/lib_version/exe/octez_print_version.exe
• Check the version again

Checklist

• Document the interface of any function added or modified (see the coding guidelines)
• Document any change to the user interface, including configuration parameters (see node configuration)
• Provide automatic testing (see the testing guide).
• For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, CHANGES.rst at the root of the repository for everything else).
• Select suitable reviewers using the Reviewers field below.
• Select as Assignee the next person who should take action on that MR