Added list all nodes API for backend, with bazel build system.

mapping/elf/BUILD.bazel

@@ -0,0 +1,9 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["core.go"],
+    importpath = "git.eve.moe/jackyyf/navigator/mapping/elf",
+    visibility = ["//visibility:public"],
+    deps = ["@net_starlark_go//starlark:go_default_library"],
+)