Genbank parser rewrite

[carreter]

Changes in this PR

Rewrite of the Genbank parser. Currently in a draft state.

Why are you making these changes?

See #434 .

Are any changes breaking? (IMPORTANT)

Yes. Changes to the structure and methods of the Genbank struct, as well as the API for the parser.

Pre-merge checklist

All of these must be satisfied before this PR is considered ready for merging. Mergeable PRs will be prioritized for review.

• [ ] New packages/exported functions have docstrings.
• [ ] New/changed functionality is thoroughly tested.
• [ ] New/changed functionality has a function giving an example of its usage in the associated test file. See primers/primers_test.go for what this might look like.
• [ ] Changes are documented in CHANGELOG.md in the [Unreleased] section.
• [ ] All code is properly formatted and linted.
• [ ] The PR template is filled out.

[github-actions[bot]]

This PR has had no activity in the past 2 months. Marking as stale.

[github-actions[bot]]

This PR has had no activity in the past 2 months. Marking as stale.