Apply clang-format for core/iwasm/compilation and core/iwasm/libraries files.
Add wasm-c-api empty_imports sample to workflow test.
And enable triggering workflow when core/config.h changes.
Enable to use BH_VPRINTF macro for platform Linux/Windows/Darwin/VxWorks to redirect the stdout output from platform os_printf/os_vprintf, or the wasi output from wasm app to the vprintf like callback function specified by BH_VPRINTF macro of cmake WAMR_BH_VPRINTF variable.
Signed-off-by: Wenyong Huang <wenyong.huang@intel.com>
