Added postInit() function to debug tool interface, for outputting any debug-tool-specific info after initialisation.

Removed `getFirmwareVersionString()` function

src/DebugToolDrivers/WCH/WchLinkBase.hpp

@@ -30,12 +30,12 @@ namespace DebugToolDrivers::Wch
 
         void close() override;
 
+        void postInit() override;
+
         [[nodiscard]] bool isInitialised() const override;
 
         std::string getSerialNumber() override;
 
-        std::string getFirmwareVersionString() override;
-
         ::DebugToolDrivers::Protocols::RiscVDebugSpec::DebugTranslator* getRiscVDebugInterface(
             const Targets::RiscV::TargetDescriptionFile& targetDescriptionFile,
             const Targets::RiscV::RiscVTargetConfig& targetConfig