Refactors Calibre Wireless Device & Calibre Library (#404)

Our esp32 consistently dropped the last few packets of the TCP transfer
in the old implementation. Only about 1/5 transfers would complete. I've
refactored that entire system into an actual Calibre Device Plugin that
basically uses the exact same system as the web server's file transfer
protocol. I kept them separate so that we don't muddy up the existing
file transfer stuff even if it's basically the same at the end of the
day I didn't want to limit our ability to change it later.

I've also added basic auth to OPDS and renamed that feature to OPDS
Browser to just disassociate it from Calibre.

---------

Co-authored-by: Arthur Tazhitdinov <lisnake@gmail.com>
Co-authored-by: Dave Allie <dave@daveallie.com>

src/network/CrossPointWebServer.h

@@ -2,7 +2,10 @@
 
 #include <WebServer.h>
 #include <WebSocketsServer.h>
+#include <WiFiUdp.h>
 
+#include <memory>
+#include <string>
 #include <vector>
 
 // Structure to hold file information
@@ -15,6 +18,16 @@ struct FileInfo {
 
 class CrossPointWebServer {
  public:
+  struct WsUploadStatus {
+    bool inProgress = false;
+    size_t received = 0;
+    size_t total = 0;
+    std::string filename;
+    std::string lastCompleteName;
+    size_t lastCompleteSize = 0;
+    unsigned long lastCompleteAt = 0;
+  };
+
   CrossPointWebServer();
   ~CrossPointWebServer();
 
@@ -25,11 +38,13 @@ class CrossPointWebServer {
   void stop();
 
   // Call this periodically to handle client requests
-  void handleClient() const;
+  void handleClient();
 
   // Check if server is running
   bool isRunning() const { return running; }
 
+  WsUploadStatus getWsUploadStatus() const;
+
   // Get the port number
   uint16_t getPort() const { return port; }
 
@@ -40,6 +55,8 @@ class CrossPointWebServer {
   bool apMode = false;  // true when running in AP mode, false for STA mode
   uint16_t port = 80;
   uint16_t wsPort = 81;  // WebSocket port
+  WiFiUDP udp;
+  bool udpActive = false;
 
   // WebSocket upload state
   void onWebSocketEvent(uint8_t num, WStype_t type, uint8_t* payload, size_t length);
@@ -56,6 +73,7 @@ class CrossPointWebServer {
   void handleStatus() const;
   void handleFileList() const;
   void handleFileListData() const;
+  void handleDownload() const;
   void handleUpload() const;
   void handleUploadPost() const;
   void handleCreateFolder() const;