Fix bad string trimming creating bogus string_views

src/dds/util/string.hpp

         ++iter;
     }
     auto riter = s.rbegin();
-    auto rend  = s.rend();
+    auto rend  = std::make_reverse_iterator(iter);
     while (riter != rend && std::isspace(*riter)) {
         ++riter;
     }
     return sview(iter, new_end);
 }
 
+inline std::string_view trim(const char* str) { return trim(std::string_view(str)); }
+
 inline std::string trim(std::string&& s) { return std::string(trim(s)); }
 
 inline bool ends_with(std::string_view s, std::string_view key) {

src/dds/util/string.test.cpp

     CHECK(!ends_with("foo.bar", "foo"));
 }
 
+void test_trim() {
+    CHECK(trim("foo") == "foo");
+    CHECK(trim("foo   ") == "foo");
+    CHECK(trim("   ").size() == 0);
+}
+
 void test_contains() {
     CHECK(contains("foo", "foo"));
     CHECK(contains("foo", ""));
 }
 
 void run_tests() {
+    test_trim();
     test_starts_with();
     test_ends_with();
     test_contains();

src/libman/parse.test.cpp

     auto kvs    = parse_string(lm_src);
     CHECK(kvs.size() == 0);
 
-    lm_src = "foo: bar";
+    CHECK(parse_string("    ").size() == 0);
+    CHECK(parse_string("\n    ").size() == 0);
+    CHECK(parse_string("#comment\n    ").size() == 0);
+
+    lm_src = "foo: bar\n ";
     kvs    = parse_string(lm_src);
     CHECK(kvs.size() == 1);
     REQUIRE(kvs.find("foo"));