pw_minimal_cpp_stdlib: More iterator support

Update pw_minimal_cpp_stdlib to include the following:
 - climits header
 - std::begin() and std::end()
 - std::find()
 - std::copy()

Change-Id: Iac5818e897daf79ff0a4c882a5a730da8e84a3f8
diff --git a/pw_minimal_cpp_stdlib/BUILD.gn b/pw_minimal_cpp_stdlib/BUILD.gn
index 97060a5..3cbe163 100644
--- a/pw_minimal_cpp_stdlib/BUILD.gn
+++ b/pw_minimal_cpp_stdlib/BUILD.gn
@@ -30,6 +30,7 @@
     "public/algorithm",
     "public/array",
     "public/cinttypes",
+    "public/climits",
     "public/cmath",
     "public/cstdarg",
     "public/cstddef",
@@ -48,6 +49,7 @@
     "public/internal/algorithm.h",
     "public/internal/array.h",
     "public/internal/cinttypes.h",
+    "public/internal/climits.h",
     "public/internal/cmath.h",
     "public/internal/cstdarg.h",
     "public/internal/cstddef.h",