fix: replace spaces with plus character

Author: anonrig

include/ada/character_sets-inl.h

@@ -517,7 +517,7 @@ constexpr uint8_t WWW_FORM_URLENCODED_PERCENT_ENCODE[32] = {
     // 18     19     1A     1B     1C     1D     1E     1F
     0x01 | 0x02 | 0x04 | 0x08 | 0x10 | 0x20 | 0x40 | 0x80,
     // 20     21     22     23     24     25     26     27
-    0x01 | 0x02 | 0x04 | 0x08 | 0x10 | 0x20 | 0x40 | 0x80,
+    0x00 | 0x02 | 0x04 | 0x08 | 0x10 | 0x20 | 0x40 | 0x80,
     // 28     29     2A     2B     2C     2D     2E     2F
     0x01 | 0x02 | 0x00 | 0x08 | 0x10 | 0x00 | 0x00 | 0x00,
     // 30     31     32     33     34     35     36     37

include/ada/url_search_params-inl.h

@@ -60,14 +60,19 @@ inline std::string url_search_params::to_string() {
   auto character_set = ada::character_sets::WWW_FORM_URLENCODED_PERCENT_ENCODE;
   std::string out{};
   for (size_t i = 0; i < params.size(); i++) {
-    auto [key, value] = params[i];
+    auto key = ada::unicode::percent_encode(params[i].first, character_set);
+    auto value = ada::unicode::percent_encode(params[i].second, character_set);
+
+    // Performance optimization: Move this inside percent_encode.
+    std::replace(key.begin(), key.end(), ' ', '+');
+    std::replace(value.begin(), value.end(), ' ', '+');
 
     if (i != 0) {
       out += "&";
     }
-    out.append(ada::unicode::percent_encode(key, character_set));
+    out.append(key);
     out += "=";
-    out.append(ada::unicode::percent_encode(value, character_set));
+    out.append(value);
   }
   return out;
 }