Fix Makie.inline!(...) for most cases

[SimonDanisch]

This should fix #2805 and #2901.
It's still not perfect, but I think at this point only a breaking change can improve upon this.

[MakieBot]

Compile Times benchmark

Note, that these numbers may fluctuate on the CI servers, so take them with a grain of salt. All benchmark results are based on the mean time and negative percent mean faster than the base branch. Note, that GLMakie + WGLMakie run on an emulated GPU, so the runtime benchmark is much slower. Results are from running:

using_time = @ctime using Backend
# Compile time
create_time = @ctime fig = scatter(1:4; color=1:4, colormap=:turbo, markersize=20, visible=true)
display_time = @ctime Makie.colorbuffer(display(fig))
# Runtime
create_time = @benchmark fig = scatter(1:4; color=1:4, colormap=:turbo, markersize=20, visible=true)
display_time = @benchmark Makie.colorbuffer(display(fig))

	using	create	display	create	display
GLMakie	40.15s (39.39, 41.03) 0.50+-	18.48s (18.22, 18.74) 0.19+-	16.87s (16.69, 17.49) 0.29+-	12.02ms (11.59, 12.40) 0.28+-	141.29ms (137.70, 147.86) 3.19+-
master	40.32s (39.90, 40.67) 0.31+-	18.65s (18.03, 19.35) 0.55+-	17.17s (16.63, 17.79) 0.41+-	11.96ms (11.80, 12.20) 0.17+-	137.63ms (135.37, 139.13) 1.56+-
evaluation	-0.40%, -0.16s invariant (-0.39d, 0.48p, 0.40std)	-0.91%, -0.17s invariant (-0.41d, 0.47p, 0.37std)	-1.79%, -0.3s invariant (-0.85d, 0.14p, 0.35std)	+0.42%, 0.05ms invariant (0.22d, 0.69p, 0.23std)	+2.59%, 3.65ms slower X (1.45d, 0.02p, 2.38std)
CairoMakie	33.49s (33.37, 33.63) 0.09+-	18.19s (18.06, 18.33) 0.10+-	2.74s (2.71, 2.76) 0.02+-	10.34ms (10.26, 10.42) 0.06+-	4.95ms (4.84, 5.02) 0.07+-
master	33.40s (33.23, 33.50) 0.08+-	18.23s (18.11, 18.40) 0.12+-	2.73s (2.71, 2.76) 0.02+-	10.45ms (10.28, 10.63) 0.10+-	5.02ms (4.79, 5.18) 0.13+-
evaluation	+0.27%, 0.09s invariant (1.01d, 0.08p, 0.09std)	-0.23%, -0.04s invariant (-0.37d, 0.50p, 0.11std)	+0.15%, 0.0s invariant (0.22d, 0.69p, 0.02std)	-1.05%, -0.11ms faster ✓ (-1.28d, 0.04p, 0.08std)	-1.47%, -0.07ms invariant (-0.71d, 0.22p, 0.10std)
WGLMakie	54.76s (54.09, 55.01) 0.31+-	27.96s (27.52, 28.57) 0.36+-	28.32s (27.77, 28.64) 0.29+-	19.13ms (18.03, 20.68) 1.01+-	1.02s (0.96, 1.05) 0.04+-
master	54.63s (54.31, 55.05) 0.25+-	28.30s (27.94, 28.83) 0.29+-	28.64s (28.08, 29.47) 0.45+-	19.00ms (17.71, 20.32) 0.82+-	1022.93ms (964.62, 1052.47) 29.22+-
evaluation	+0.24%, 0.13s invariant (0.46d, 0.41p, 0.28std)	-1.22%, -0.34s invariant (-1.05d, 0.07p, 0.32std)	-1.15%, -0.33s invariant (-0.87d, 0.14p, 0.37std)	+0.70%, 0.13ms invariant (0.15d, 0.79p, 0.92std)	-0.64%, -0.01s invariant (-0.20d, 0.72p, 0.03std)

[SimonDanisch]

I've tested this on a few platforms with Pluto, IJulia, VSCode and REPL and things seem to work mostly as expected besides a few expected issues with WGLMakie, because the display system via JSServe and the browser is a bit more complex.
E.g. inline!(false) doesn't help to open a browser window with WGLMakie when in VSCode with active plotpane, because it would need to communicate this to JSServe which does the actual displaying.
The good news is, disabling the plotpane now at least starts opening a browser window with WGLMakie, and the same is true for the REPL.
I hope this won't introduce any other weird issues with E.g. documenter, but I think most corner cases should work fine now (but are hard to test).