fix(build): fix a link error on macOS

[acelyc111]

#1602

Remove the _test postfix of function tests to prevent the link errors on macOS look like:

[ 50%] Linking CXX executable backup_restore_test
ld: can't write output file to 'backup_restore_test' because that path is a directory
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [src/test/function_test/backup_restore_test/backup_restore_test] Error 1
make[1]: *** [src/test/function_test/backup_restore_test/CMakeFiles/backup_restore_test.dir/all] Error 2
make[1]: *** Waiting for unfinished jobs....