Accessible from main menu Help > About Meshroom, or by pressing "F1". Provides info about Meshroom version + useful links and related Open Source Licenses.
* load COPYING.md from Meshroom/AliceVision files (either provided with the standalone package or online) + translate them to HTML for display (added `markdown` package in requirements)
* request.js: centralize function to open file urls
* provide system info from MeshroomApp (exposed as contextProperty)
Fix synchronization with 3D camera selection when the corresponding image has not been instantiated in ImageGallery (outside visible viewport).
* SortFilterDelegateModel: add "find" method
* ImageGallery
* move passive selection logic out of the Delegate as it's created only when visible in the GridView
* use SortFilterDelegateModel.find to get item index based on selected "viewId" and set GridView's currentIndex
* use variant for filterValue and implement different logics to test filter matching based on value type
* allow redefinition of modelData and respectFilter functions to customize logic from outisde if need be
* add convenient 'reverseSortOrder' method
