Ensure all IOP_CS_RAW modules work without snapping for sensor pattern

[jenshannoschwalm]

UPDATED (2)
These commits

• adds xtrans/filters data to the piece struct
• provides dt_dev_prepare_piece_cfa() setting correct filters and xtrans pattern to piece data
  according to specified roi if the piece module works in IOP_CS_RAW
• makes sure pixelpipe and tiling code provide corrected CFA patterns in the piece struct before
  calling process(), process_cl() or any tiling variant
• allows all IOP_CS_RAW modules to choose CFA filter/xtrans data either from piece or pipe
  without need to calculate those internally thus reducing code complexity.

Why doing so?
Snapping to a sensor pattern restricts precision of roi dimensions and displacements if distorting
modules (like lens, rotate&perspective...) or even simple crop or orientation also set roi.
In darkroom mode this is of very little significance, for exports there is a clear benefit.
Performance gains are neglectable.

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Modules working in IOP_CS_RAW regularly need to know the photosite color channel for a given location,
for this they require correct CFA pattern information via filters or the xtrans pattern.

We have inline functions or macros as FC() or FCxtrans(), they:

• can use xtrans/filters data in pipe->dsc provided by rawprepare (pipe data).
  While doing so, they must use the roi_in->x/y displacements with a subtle performance cost
• can use corrected filters/xtrans data (piece data) and possibly use more performant inline functions

Fixed and checked for OpenCL/CPU and both sensors:

1. All demosaicers, cacorrect, hotpixels, rawdenoise and highlights reconstruction modes use piece data
2. invert is safe as it uses pipe data correctly
3. rasterfile is safe as is doesn't use CFA data
4. temperature now uses piece data

Reminder:
Generic tiling still uses CFA snappers for overlapping, not required any more.

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The second commit is about OpenCL VNG performance

[jenshannoschwalm]

@TurboGit a pretty large single commit. No visible differences but for sure we will have subtle differences when exporting if lens, flip or alike is included so the integration tests will remind you. This would be reference now :-)

[jenshannoschwalm]

The second commit significantly improves OpenCL VNG performance as it avoids kernel calls.

[jenshannoschwalm]

Release notes:

1. Redesign of the pixelpipe allows positioning, distortion and crops with precision to a single pixel
2. Performance gains for all OpenCL VNG (dual) demosaicers