Improve history handling.

[nbren12]

Earth-2 MIP Pull Request

Description

Improve handling of history. Previously models with history (e.g. DLWP) could not be initialized with data sources without history. A work-around was to manually building a new data source, and made the notebooks/examples messy. Also, this was preventing using dlwp for ensemble inference with CDS inits for example.

I added support for history to the function get_initial_condition_for_model, which is used by all the inference routines.

Checklist

• [x] I am familiar with the Contributing Guidelines.
• [x] New or existing tests cover these changes.
• [x] The documentation is up to date with these changes.
• [x] The CHANGELOG.md is up to date with these changes.
• [ ] An issue is linked to this pull request.

Dependencies

[nbren12]

/blossom-ci

[nbren12]

/blossom-ci

[yairchn]

LGTM