Began refactoring target descriptor structs.

This is incomplete - a partial commit of a substantial peice of work

src/Targets/TargetDescriptor.cpp

@@ -0,0 +1,50 @@
+#include "TargetDescriptor.hpp"
+
+#include "src/Exceptions/InternalFatalErrorException.hpp"
+
+namespace Targets
+{
+    TargetDescriptor::TargetDescriptor(
+        const std::string& name,
+        TargetFamily family,
+        const std::string& marketId,
+        const std::string& vendorName,
+        const std::map<std::string, TargetAddressSpaceDescriptor>& addressSpaceDescriptorsByKey,
+        const std::map<std::string, TargetPeripheralDescriptor>& peripheralDescriptorsByKey,
+        const std::vector<TargetVariant>& variants,
+        const BreakpointResources& breakpointResources
+    )
+        : name(name)
+        , family(family)
+        , marketId(marketId)
+        , vendorName(vendorName)
+        , addressSpaceDescriptorsByKey(addressSpaceDescriptorsByKey)
+        , peripheralDescriptorsByKey(peripheralDescriptorsByKey)
+        , variants(variants)
+        , breakpointResources(breakpointResources)
+    {}
+
+    std::optional<
+        std::reference_wrapper<const TargetAddressSpaceDescriptor>
+    > TargetDescriptor::tryGetAddressSpaceDescriptor(const std::string& key) const {
+        const auto descriptorIt = this->addressSpaceDescriptorsByKey.find(key);
+
+        if (descriptorIt == this->addressSpaceDescriptorsByKey.end()) {
+            return std::nullopt;
+        }
+
+        return std::cref(descriptorIt->second);
+    }
+
+    const TargetAddressSpaceDescriptor& TargetDescriptor::getAddressSpaceDescriptor(const std::string& key) const {
+        const auto descriptor = this->tryGetAddressSpaceDescriptor(key);
+        if (!descriptor.has_value()) {
+            throw Exceptions::InternalFatalErrorException(
+                "Failed to get address space descriptor \"" + std::string(key)
+                    + "\" from target descriptor - descriptor not found"
+            );
+        }
+
+        return descriptor->get();
+    }
+}