Merge branch 'main' of https://github.com/secondlife/viewer

.github/workflows/build.yaml

build.sh

doc/contributions.txt

indra/cmake/CMakeLists.txt

indra/cmake/Copy3rdPartyLibs.cmake

indra/cmake/ICU4C.cmake

indra/llappearance/llavatarappearance.cpp

indra/llappearance/llavatarappearance.h

indra/llappearance/llwearable.cpp

indra/llcharacter/llmultigesture.cpp

indra/llcharacter/llmultigesture.h

indra/llcommon/CMakeLists.txt

indra/llcommon/llcoros.cpp

indra/llcommon/llstring.cpp

indra/llcommon/llstring.h

indra/llcommon/llsys.cpp

indra/llimage/llimage.cpp

indra/llimage/llimage.h

indra/llimage/llimagepng.cpp

indra/llimage/llimageworker.cpp