Handle nodes move and auto-layout on Python side by using GraphLayout and MoveNodeCommand.
* Node QML component relies on underlying core.Node object's position
* MoveNodeCommand is called after a Node has been dragged
* partial/full auto-layout for specific graph operations (Duplication, Augmentation...) are now part of those operations
* serialized position in node data allows to properly restore nodes coordinates on undo/redo
* remove all layout/node moving code from QML
Improve node serialization/deserialization to be able to recreate the exact same node in the graph when loading a meshroom project, even if the corresponding node's description has changed or does not exist anymore. This allows to recover already computed data on disk, without being impacted by changed uids. CompatibilityNode also provides an on-demand upgrade system to turn into a Node that meets the current node description (if possible).
* new abstract class BaseNode, base class for Node and CompatibiliyNode
* Node: serialize everything needed to spawn a CompatibilityNode with precomputed outputs: inputs, uids, parallelization settings, unresolved internal folders and outputs
* node_factory: handles node deserialization and compatibility issues to create either a Node or a CompatibilityNode
* add compatibility unit tests
First version of retrocompatibility, allowing to load files referencing removed or type-incompatible attributes.
* add node_factory to centralize node instantiation
* discard invalid attributes (i.e. not part of the node description anymore or with incompatible value type) when loading a file
* raise on unknown nodes
* add 'core.exception' module to declare Meshroom's exception types
* add 'sfmPipeline', 'mvsPipeline' and 'photogrammetryPipeline' instantiating nodes in an existing graph
* rename main function (creating a new Graph) 'photogrammetry' + create a Publish node if 'output' is specified
* create two separate drop areas when adding images to the project (add images / augment reconstruction)
* add sfm augmentation in graph after intrinsics have been built
* move LiveSfmManager.stepCreated to Reconstruction.sfmAugmented
* add utility methods in Reconstruction to get all images/views used in the graph
* ui: perform local auto-layout on sfm augmentation on created nodes
* add the notion of a current SfM node in the Reconstruction
* retrieve views and poses from this node when selected or when its status changes
* use this information to display a status on Images in ImageGallery
* keep an internal reference to the "main" CameraInit node an update it according to graph modification
* expose viewpoints model as a property
* TODO: handle multiple CameraInit nodes
* extract UIGraph from Reconstruction: base class that wraps a core.Graph, without knowledge of photogrammetry pipeline
* ChunksMonitor: watch NodeChunks status files for external changes to keep UI updated even when the graph is being computed externally
* Reconstruction inherits UIGraph with photogrammetry specific features
