add default to theme methods

[pepijndevos]

Description

Fixes #3043

As discussed with @SimonDanisch instead of adding a nothing method, add default arguments

Type of change

Delete options that do not apply:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist

• Added an entry in NEWS.md (for new features and breaking changes)
• Added or changed relevant sections in the documentation
• Added unit tests for new algorithms, conversion methods, etc.
• Added reference image tests for new plotting functions, recipes, visual options, etc.

[SimonDanisch]

Thank you! :)
Would it be possible to add some simple sanity tests to:
https://github.com/MakieOrg/Makie.jl/blob/master/test/scenes.jl

[pepijndevos]

Of course

[SimonDanisch]

Thank you!