This change introduces versioning to the identity document format.

The Version type is introduced to captured this. Importantly, it is very restricted in its construction and API. Since we primarily only care about serializing and deserializing documents, the Version is constructed via Deserialize. The only other ways to get a Version is to use the IDENTITY_VERSION constant or by using Version::default.

The Deserialize implementation ensures that the version is within the accepted bounds, i.e. that it is not 0 and that it is not a version that may not have been released yet – the user may be running a previous client. If it does encounter a future version, it will provide a helpful error message to check version compatabilities, and possibly upgrade their binaries.

Note that changing the Doc means that the hashes for tests change. This requires updating a few of the library tests and many of the CLI tests. One important note is the introduction of the advance_timestamp helper in cob::identity::test, which allows us to manipulate the timestamp so that we keep a stable order for the timeline tests and get the correct series of events.

Changes:

• Rebased on f6b2c5110741b776655eca8228ec66de40b7243d
• Added docs to Version
• Moved radicle_cob::git::STABLE_TIME to this patch

Changes:

• Use function for setting default value of document version
• Update docs for with_timestamp

Changes:

• Simplify version check by removing the ACCEPTED_VERSIONS static and using a range check instead.
• Introduced Version::new and Version::try_from to help with construction of a Version, along with VersionError for error cases.

Changes:

• Skip serializing Doc::version when the version <= 1

Changes:

• Use NonZeroU32 since we do not allow the version 0

Changes:

• Simplify deserialize of version

Changes:

• Clean up typos and comments
• More concise error message for unknown versions
• Renamed FutureVersion to UnkownVersion
• Rename deserialize_default_version to missing_version
• Add RawDoc::version and Doc::version getters
• VersionError::verbose for more verbose version of the error

Rebase.