%Ops table should be authoritative - No need for graphics traits or track-graphics multi method

[dwarring]

I.e. refactor PDF::Content::Ops to be more like HTML::Canvas, which has everything in the one Op table.

[dwarring]

Attempted on branch op-refactor. But attempted conversion of Tm gives:
P6opaque: no such attribute '@!TextMatrix' in type PDF::Content::Ops when trying to get a value
in method at /home/david/git/perl6-PDF-Content/lib/PDF/Content/Ops.pm (PDF::Content::Ops) line 497
in method opn at /home/david/git/perl6-PDF-Content/lib/PDF/Content/Ops.pm (PDF::Content::Ops) line 569
in method op at /home/david/git/perl6-PDF-Content/lib/PDF/Content/Ops.pm (PDF::Content::Ops) line 577
in method at /home/david/git/perl6-PDF-Content/lib/PDF/Content/Ops.pm (PDF::Content::Ops) line 810
in method FALLBACK at /home/david/git/perl6-PDF-Content/lib/PDF/Content/Ops.pm (PDF::Content::Ops) line 822
in any at gen/moar/m-Metamodel.nqp line 3096
in sub at /home/david/git/perl6-PDF-Content/lib/PDF/Content/Ops.pm (PDF::Content::Ops) line 207
in block at t/ops.t line 100

[dwarring]

Abandoning refactor at the moment.