Fix crash when editing transform mask too actively
- Now KisSpontaneousJob has an 'exclusive' property, which guarantees that now other update jobs are not running in parallel
- KisModifyTransformMaskCommand mush not call m_mask->recaclulateStaticImage() directly, it doesn't guarantee exclusive access to a paint device, which can cause a crash (because the transform worker calls KisPaintDevice::purge(), which demands exclusive access).
BUG:395224