propagate args as-is to convert_arguments(trait, args...)

[aplavin]

Description

Fixes #3847
The Makie 0.21 version doesn't propagate convert_arguments arguments to convert_arguments(trait) directly, making some common conversions impossible (#3847 for example). Turns out, the fix (this PR) is pretty simple.

Type of change

Delete options that do not apply:

• Bug fix (non-breaking change which fixes an issue)

Checklist

• Added unit tests for new algorithms, conversion methods, etc.

[SimonDanisch]

The new expand_dimensions was introduced for a reason, so this should not be the correct fix...
I'm surprised that this passes tests though, so I guess I need to investigate this a bit.
In 0.21 you will need to start overloading expand_dimensions for your example. This should get documented a bit better!

[aplavin]

This PR doesn't remove expand_dimensions, it still gets called one step downstream at

Makie.jl/src/conversions.jl

Lines 6 to 12 in 746b03f

	function convert_arguments(CT::ConversionTrait, args...)
	expanded = expand_dimensions(CT, args...)
	if !isnothing(expanded)
	return convert_arguments(CT, expanded...)
	end
	return args
	end

.
That's why the tests keep working.

[SimonDanisch]

Ok thank you! I still think this was covering some edge case and that for your overload to work properly you will need to switch to overloading expand_dimensions. But I may be mistaken, those last changes where done a bit in a rush.
I will need to take a look at it tomorrow.

[aplavin]

If arguments are not propagated directly from convert_arguments(plottype) to convert_arguments(trait) (as it currently is in 0.21), then the easiest way to actually overload convert_arguments for all point-based plots is to define a bunch of convert_arguments(::Type{Scatter}), convert_arguments(::Type{Line}), ... manually. This is definitely more approachable than being required to plug into yet another mechanism, expand_dimensions.

Defining all those methods manually is feasible, of course, but would be unfortunate to lose the simplicity and convenience of overloading convert_arguments(::PointBased) that works in 0.20.

[SimonDanisch]

We will need to think more about how to streamline x,y,z arguments in Makie and how to decouple it from convert_arguments.
Since i couldn't find any corner case that stopped working with this, we might as well merge it for now!

[SimonDanisch]

Thank you!