Enable signet chain configs

This enables adding of signet chain configs in bitcoin.conf.
This enables running of multiple signets with diffrent configurations

i.e
chain=signet_xxxx

[signet_xxxx]
seednodes=x.x.x.x
signetchallenge=xxxxxxxxx

src/common/args.cpp

@@ -394,6 +394,33 @@ std::vector<common::SettingsValue> ArgsManager::GetSectionArg(const std::string&
     return result;
 }
 
+template <typename Key, typename Value, typename SectionKey>
+void ArgsManager::AddConfigArg(const Key& key, const Value& value, SectionKey sectionKey)
+{
+    auto& section = m_settings.ro_config[sectionKey];
+    section[key].push_back(value);
+}
+
+void ArgsManager::UpdateConfigFromSection(const std::string& section, const std::string& strArg)
+{
+    auto arg = GetSectionArg(section, strArg);
+    for(auto& sv : arg) {
+        LOCK(cs_args);
+        AddConfigArg(strArg, sv, m_network);
+    }
+}
+
+void ArgsManager::ReadSignetChainConfigs()
+{
+    const std::string SIGNET_CHAIN_PREFIX = "signet_";
+
+    const std::string chain = GetArg("-chain", "");
+    if (chain.starts_with(SIGNET_CHAIN_PREFIX)){
+        UpdateConfigFromSection(chain, "signetchallenge");
+        UpdateConfigFromSection(chain, "seednode");
+    }
+}
+
 std::vector<std::string> ArgsManager::GetArgs(const std::string& strArg) const
 {
     std::vector<std::string> result;

src/common/args.h

@@ -253,6 +253,29 @@ class ArgsManager
      */
     std::vector<common::SettingsValue> GetSectionArg(const std::string& section, const std::string& strArg) const;
 
+    /**
+     * Adds a configuration argument to a specified section in the configuration settings.
+     *
+     * @param key The key to be added to the configuration section.
+     * @param value The value to be associated with the specified key.
+     * @param sectionKey The section key identifying the section where the key-value pair will be added.
+     */
+    template <typename Key, typename Value, typename SectionKey>
+    void AddConfigArg(const Key& key, const Value& value, SectionKey sectionKey);
+
+    /**
+     * Updates the configuration settings by adding arguments from a specified section.
+     *
+     * @param section The name of the section from which to retrieve arguments.
+     * @param strArg The key whose associated arguments are to be retrieved and added to the configuration settings.
+     */
+    void UpdateConfigFromSection(const std::string& section, const std::string& strArg);
+
+    /**
+     * Read singnet chain args if signet chain arg is provided 
+    */
+    void ReadSignetChainConfigs();
+
     /**
      * Return a vector of strings of the given argument
      *

src/common/config.cpp

@@ -196,6 +196,9 @@ bool ArgsManager::ReadConfigFiles(std::string& error, bool ignore_invalid_keys)
             for (const std::string& conf_file_name : conf_file_names) {
                 tfm::format(std::cerr, "warning: -includeconf cannot be used from included files; ignoring -includeconf=%s\n", conf_file_name);
             }
+
+            // Read signet args of the provided chain and update the signet config
+            ReadSignetChainConfigs();
         }
     }
 

src/util/chaintype.cpp

@@ -29,7 +29,7 @@ std::optional<ChainType> ChainTypeFromString(std::string_view chain)
         return ChainType::MAIN;
     } else if (chain == "test") {
         return ChainType::TESTNET;
-    } else if (chain == "signet") {
+    } else if (chain == "signet" || chain.starts_with("signet_") ) {
         return ChainType::SIGNET;
     } else if (chain == "regtest") {
         return ChainType::REGTEST;