They were a neat idea while they lasted. But now, it's time for
categorized transform nodes, where matrices with
GSK_MATRIX_CATEGORY_2D_TRANSLATE are the exact replacement.
Renderers have not been adapted for this purpose, so they (continue to)
run slow paths.
Some of the flags got lost in the meson transition or were demoted from
error flags to warning flags.
This commit reintroduces them.
It also includes fixes for the code that had warnings with those flags.
The big one being -Wshadow.
And of course, gsk_render_node_get_name() is gone, too.
The replacement is of course debug nodes.
As a side effect, GskRenderNode is now *really* immutable.
This is a special case of the transform node that does a 2D translation.
The implementation in the Vulkan and GL renderers is crude and just does
the same as the transform node.
Nothing uses that node yet.
Add a setter for per-renderer debug flags, and use
them where possible. Some places don't have easy access
to a renderer, so this is not complete.
Also, use g_message instead of g_print throughout.
