Support version tagging

[changhiskhan]

Git-like version tags make it easier to manage lots of versions and quickly know which versions are released for example.

Version tags should be written to the version Manifest (protos: https://github.com/eto-ai/lance/blob/main/protos/format.proto#L74, rust: https://github.com/eto-ai/lance/blob/main/rust/src/format/manifest.rs#L55)

Write

1. Manifest file is written here when writing a dataset.
2. The version tag should be passed down from python -> pyo3 -> core lance (see step 1).
3. Currently only WriteParams are passed down to core lance. The API should distinguish writeparams and metadata so it's probably best to create a new struct that can be extended to hold (1) tags, (2) schema metadata, and (3) version-specific metadata

Read

The tag needs to be added to the PyDict in the pyo3 code: https://github.com/eto-ai/lance/blob/main/python/src/dataset.rs#L183

Checkout

On the python side, add a convenience feature to checkout a tag instead of a specific version number