refactor(node,render): route oaknode->oakrender calls through the C ABI

- oakrender cache C API: add create_for_node (four cache kinds),
  get_uuid, request, load/save_state, set_saving_enabled,
  set_passthrough, get_passthroughs, get_valid_cache_filename,
  get_timebase, lock/unlock, invalidate_range (rational variant),
  get_native (C++ only, for the in-module PreviewAutoCacher)
- Node's four caches become owned OakRenderCache value handles; all
  cache access in node.cpp/clip/viewer/traverser/serializers goes
  through the C ABI
- oaknode_node_get_video_frame_cache returns an addref'd
  OakRenderCache; drop OakNodeFrameCache; oaktask precache/export and
  oakrender_video_ticket_params take the value handle
- color: OCIOBaseNode/OCIOLutNode hold OakColorProcessor handles
  (dtors added); oakrender gains color_processor_create_transform/
  create_lut/create_grading_primary/get_native and LUT library
  queries, keeping all OCIO transform construction inside oakrender;
  oaknode gains colormanager_wrap_borrowed/get_native
- RenderManager::instance() check -> oakrender_manager_available();
  cancel_video_tasks and disk cache path go through manager C API
- remaining node->render C++ symbol: only olive::Texture::~Texture
  via Variant's shared_ptr payload (recorded exception, same class as
  the UndoCommand inheritance)

Tests: new cache/color/manager/colormanager cases; all standalone
trees green (common 196, codec 22, audio 40, task 112, render 63,
timeline 125, node 98, plugin 102).

include/render/ticket.h

@@ -30,6 +30,7 @@
 #include "olive/core/oakcore/audioparams.h"
 #include "olive/core/oakcore/samplebuffer.h"
 #include "render/error.h"
+#include "render/cache.h"
 #include "render/color.h"
 #include "render/renderer.h"
 
@@ -89,7 +90,7 @@ typedef struct oakrender_video_ticket_params {
 	int force_channel_count; /**< 0 = off. */
 	OakColorProcessor force_color_output; /**< Borrowed; empty ctx = none. */
 	OakColorTransform force_color_transform; /**< By value; empty ctx = default. */
-	OakNodeFrameCache *cache; /**< Borrowed frame cache, may be NULL. */
+	OakRenderCache cache; /**< Borrowed frame cache; empty ctx = none. */
 } oakrender_video_ticket_params;
 
 /**