Allow an optional origin in world frame constructors - #1534

Closes #1141.

Allow Frame.worldXY(), Frame.worldYZ(), and Frame.worldZX() to take an optional origin as a coordinate sequence or Point. Calls without an argument still use [0, 0, 0], and each frame keeps its existing axis directions.

The constructor docstrings show the new usage, and a parameterized test covers all three frames with both accepted point forms. I also added the changelog entry and contributor credit required by CONTRIBUTING.md.

What type of change is this?

• Bug fix in a backwards-compatible manner.
• New feature in a backwards-compatible manner.
• Breaking change: bug fix or new feature that involve incompatible API changes.
• Other (e.g. doc update, configuration, etc)

Checklist

• I added a line to CHANGELOG.md under Unreleased.
• I ran the full pytest suite: 1,017 passed, 12 skipped.
• I ran project-wide lint with no errors. ruff check . reports 12 existing issues outside the changed files; ruff check and ruff format --check pass for the changed Python files.
• I added new functions/classes and made them available on a second-level import (not applicable; existing constructors were extended).
• I added tests for the new behavior.
• I updated the constructor documentation.

The frame module doctests also pass (19 passed).