BuildSystem: Rework the whole cmake build system

Now files are installed using the install() command instead of manually
copying files to their destinations. This allows automatic recompilation
of headers that did not work previously

userspace/echo/CMakeLists.txt

@@ -1,16 +1,8 @@
-cmake_minimum_required(VERSION 3.26)
-
-project(echo CXX)
-
 set(SOURCES
 	main.cpp
 )
 
 add_executable(echo ${SOURCES})
-target_compile_options(echo PUBLIC -O2 -g)
-target_link_libraries(echo PUBLIC libc)
+banan_link_library(echo libc)
 
-add_custom_target(echo-install
-	COMMAND ${CMAKE_COMMAND} -E copy ${CMAKE_CURRENT_BINARY_DIR}/echo ${BANAN_BIN}/
-	DEPENDS echo
-)
+install(TARGETS echo)