Correct figure size when displaying inline in iTerm2

[asinghvi17]

For all those who use Mac + iTerm2, here's something you can execute in your terminal with TerminalExtensions.jl loaded, which should give Makie plots the correct physical size on screen even with px_per_unit != 1.

for mime in TerminalExtensions.iTerm2.iterm2_mimes
    @eval begin
        function Base.display(d::TerminalExtensions.iTerm2.InlineDisplay, m::MIME{Symbol($mime)}, scene::Makie.Scene)
            buf = IOBuffer()
            show(TerminalExtensions.iTerm2.Base64.Base64EncodePipe(buf), m, scene)
            TerminalExtensions.iTerm2.prepare_display_file(; filename="Makie.jl scene", inline=true, width = string(Makie.widths(Makie.pixelarea(scene)[])[1]) * "px", height = string(Makie.widths(Makie.pixelarea(scene)[])[2]) * "px")
            write(stdout, take!(buf))
            write(stdout,'\a')
        end
        Base.display(d::TerminalExtensions.iTerm2.InlineDisplay, m::MIME{Symbol($mime)}, fig::Makie.Figure) = Base.display(d, m, fig.scene)
        Base.display(d::TerminalExtensions.iTerm2.InlineDisplay, m::MIME{Symbol($mime)}, fig::Makie.FigureAxisPlot) = Base.display(d, m, fig.figure)
    end
end

I'll see about making this a package extension at some point.