libs : rename libcommon -> libllama-common (#21936)

* cmake : allow libcommon to be shared

* cmake : rename libcommon to libllama-common

* cont : set -fPIC for httplib

* cont : export all symbols

* cont : fix build_info exports

* libs : add libllama-common-base

* log : add common_log_get_verbosity_thold()

vendor/cpp-httplib/CMakeLists.txt

@@ -5,6 +5,8 @@ find_package(Threads REQUIRED)
 
 llama_add_compile_flags()
 
+set(CMAKE_POSITION_INDEPENDENT_CODE ON)
+
 add_library(${TARGET} STATIC httplib.cpp httplib.h)
 
 # disable warnings in 3rd party code