Figure.wiggle: Deprecate parameter "color" (remove in v0.12.0) and add "fillpositive"/"fillnegative"

[michaelgrund]

Description of proposed changes

Addresses #1617.

Parameter color is deprecated and replaced by the two new parameters

• fillpositive and
• fillnegative.

Reminders

• Run make format and make check to make sure the code follows the style guide.
• Add tests for new features or tests that would have caught the bug that you're fixing.
• Add new public functions/methods/classes to doc/api/index.rst.
• Write detailed docstrings for all functions/methods.
• If wrapping a new module, open a 'Wrap new GMT module' issue and submit reasonably-sized PRs.
• If adding new functionality, add an example to docstrings or tutorials.

Slash Commands

You can write slash commands (/command) in the first line of a comment to perform
specific operations. Supported slash commands are:

• /format: automatically format and lint the code
• /test-gmt-dev: run full tests on the latest GMT development version

[michaelgrund]

/format

[seisman]

I'd like to see this PR being merged into the main branch before the v0.8.0 release. Do you think you have time to finish it in the next few days? @michaelgrund

[michaelgrund]

I'd like to see this PR being merged into the main branch before the v0.8.0 release. Do you think you have time to finish it in the next few days? @michaelgrund

Yes will work on it end of the week @seisman.

[seisman]

Still need to add some tests to check what happens when color and fill_positive/fill_negative are used.

[michaelgrund]

Still need to add some tests to check what happens when color and fill_positive/fill_negative are used.

Done @seisman !