Stitching scans

[krupkat]

Add support for stitching scans (https://docs.opencv.org/4.x/d2/d8d/classcv_1_1Stitcher.html#a114713924ec05a0309f4df7e918c0324ac706a6a118a4a648fef8b2fca5950e2a):

Howto

The value is selected here: https://github.com/krupkat/xpano/blob/dee2e45635bf9ebaa88b8f098bf8378765f653be/xpano/algorithm/algorithm.cc#L234

Extend stitching user options with a new enum (panorama / scans): https://github.com/krupkat/xpano/blob/dee2e45635bf9ebaa88b8f098bf8378765f653be/xpano/algorithm/options.h#L82

• the new enum will need a Label function and a constant array with all values, please check the other examples

Add a widget to select the value in gui (use utils::imgui::ComboBox for selecting an enum value): https://github.com/krupkat/xpano/blob/dee2e45635bf9ebaa88b8f098bf8378765f653be/xpano/gui/panels/sidebar.cc#L301

If Scans mode is selected

• disable projection types widget + wave correction in the gui
• add an if statement in the Stitch function when setting up stitcher and set the values according to stitcher.cc

Stretch goal

Test on real scans, compare the two modes and add the images to the PR.