Fixes and new apps (#30)

- M5 Unit Modules library + M5 Unit Test app
- Minor fixes for TodoList, TwoEleven, Snake, Brainfuck and Breakout
- Fixed SerialConsole to use the uart controller as it was broken in one of the many updates
- Fixed keyboard input in TwoEleven, Breakout, Magic8Ball and Snake
- Bluetooth Media Keys app, supports pressing physical keys to trigger the corresponding buttonmatrix button
- Epub Reader app

Apps/EpubReader/main/Source/SimpleXmlParser.h

@@ -0,0 +1,90 @@
+#pragma once
+
+#include <string>
+#include <vector>
+#include <functional>
+#include <cstdint>
+
+/**
+ * SimpleXmlParser - A buffered XML parser for reading attributes
+ * Adapted from microreader for Tactility.
+ */
+class SimpleXmlParser {
+public:
+    typedef std::function<int(char* buffer, size_t maxSize)> StreamCallback;
+
+    SimpleXmlParser();
+    ~SimpleXmlParser();
+    SimpleXmlParser(const SimpleXmlParser&) = delete;
+    SimpleXmlParser& operator=(const SimpleXmlParser&) = delete;
+    SimpleXmlParser(SimpleXmlParser&&) = delete;
+    SimpleXmlParser& operator=(SimpleXmlParser&&) = delete;
+
+    bool openFromMemory(const char* data, size_t dataSize);
+    bool openFromStream(StreamCallback callback);
+    void close();
+
+    enum class NodeType {
+        None = 0,
+        Element,
+        Text,
+        EndElement,
+        Comment,
+        ProcessingInstruction,
+        CDATA,
+        EndOfFile
+    };
+
+    bool read();
+    NodeType getNodeType() const { return currentNodeType_; }
+    const std::string& getName() const { return currentName_; }
+    bool isEmptyElement() const { return isEmptyElement_; }
+    std::string getAttribute(const char* name) const;
+    
+    // For text nodes
+    const std::string& getText() const { return currentValue_; }
+
+private:
+    const char* memoryData_ = nullptr;
+    size_t memorySize_ = 0;
+    bool usingMemory_ = false;
+
+    StreamCallback streamCallback_;
+    bool usingStream_ = false;
+    size_t streamPosition_ = 0;
+    bool streamEOF_ = false;
+
+    static constexpr size_t BUFFER_SIZE = 4096;
+    uint8_t* buffer_ = nullptr;
+    size_t bufferStartPos_ = 0;
+    size_t bufferLen_ = 0;
+    size_t filePos_ = 0;
+
+    char getByteAt(size_t pos);
+    bool loadBufferAround(size_t pos);
+    bool skipWhitespace();
+    bool matchString(const char* str);
+    char readChar();
+    char peekChar();
+
+    struct Attribute {
+        std::string name;
+        std::string value;
+    };
+
+    NodeType currentNodeType_ = NodeType::None;
+    std::string currentName_;
+    std::string currentValue_;
+    bool isEmptyElement_ = false;
+    std::vector<Attribute> attributes_;
+
+    bool readElement();
+    bool readEndElement();
+    bool readText();
+    bool readComment();
+    bool readCDATA();
+    bool readProcessingInstruction();
+    void parseAttributes();
+    std::string readElementName();
+    void skipToEndOfTag();
+};