misc: bump version to 26.0.0

fix(viz): crash when picking empty images

enh(filter): implement transform before resampling

enh(core): make data validator configurable

enh(viz): add priority attribute to order negato rendering

fix(io): graphic data of fiducials series was not properly read

enh(core): configure a service with a string

enh(core): function to add done work units

refactor(viz): return cell index when picking a mesh

feat(io): calibration data adaptation for complex calibration

refactor(io): convert to doctest

refactor(test): ported many tests to doctest

fix(viz): minor rendering fixes

refactor(core): enhance filter service signals

refactor(core): use doctest in sight::service and sight::app tests