Build for TW was broken because TW switched to ffmpeg-5 as default. Fix by updating to current dev status. This also fixes several issues in OpenBoard. Upstreamed patches are removed and some new patches added. The build system now uses cmake instead of qmake. The generated package now better conforms to FHS by placing configuration files to /etc/openboard.

- update to version 1.7.0~git20221129.9de37af
- feat: user configurable shortcuts
* replace 0460-shortcut-configuration.patch by updated
0686-shortcut-configuration.patch
* add 9686-cmake-add-shortcut-manager.patch
add new files to CMakeLists.txt
- fix: background drawing when switching page size
* update 0551-common-background-drawing.patch
- fix: mirror pixmap size
* update 0569-scale-mirror-pixmap.patch
- remove upstreamed patches
* remove upstreamed 0604-qt-5.12-compatibility.patch
* remove upstreamed 0629-bug-ruler.patch
* remove upstreamed 0633-improve-displaymanager.patch
* remove upstreamed 0637-fix-pdf-background-export.patch
* remove upstreamed 0641-fix-font-handling.patch
* remove upstreamed 0649-fix-pdf-export-scaling.patch
- chore: replace qmake by cmake build system
* remove 0651-chore-reorganize-linux-build.patch
* add 0698-add-cmake-build-system.patch
- fix: page size for PDF export
* add 0677-pdf-export-page-size.patch
- disable software update from openboard web page
* add 9117-disable-software-update.patch