Make model code compileable

This disables some application level logic, but I'm going to rewrite
that using Lager anyway.

core/src/support/jsonconv.cpp

@@ -0,0 +1,108 @@
+#include "JellyfinQt/support/jsonconv.h"
+
+namespace Jellyfin {
+namespace Support {
+
+
+QString uuidToString(const QUuid &source) {
+    QString str = source.toString();
+    // Convert {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx} (length: 38)
+    //      to xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx       (lenght: 32)
+    return QString(str.mid(1, 8) + str.mid(10, 4) + str.mid(15, 4) + str.mid(20, 4) + str.mid(25 + 12));
+}
+QUuid stringToUuid(const QString &source) {
+    if (source.size() != 32) throw new ParseException("Error while trying to parse JSON value as QUid: invalid length");
+    // Convert xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx       (length: 32)
+    //      to {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx} (length: 38)
+    QString qtParseableString;
+    qtParseableString.reserve(38);
+    qtParseableString +=  QStringLiteral("{")
+            + source.mid(0, 8)
+            + QStringLiteral("-")
+            + source.mid(8, 4)
+            + QStringLiteral("-")
+            + source.mid(12, 4)
+            + QStringLiteral("-")
+            + source.mid(16, 4)
+            + QStringLiteral("-")
+            + source.mid(20, 12)
+            + QStringLiteral("}");
+    return QUuid(qtParseableString);
+}
+
+// Trivial converters for built-in classes and simple types
+
+// int
+template <>
+int fromJsonValue(const QJsonValue &source) {
+    if (!source.isDouble()) throw new ParseException("Error while trying to parse JSON value as integer: not an integer");
+    return source.toInt();
+}
+
+template <>
+QJsonValue toJsonValue(const int &source) {
+    return QJsonValue(source);
+}
+
+// bool
+template <>
+bool fromJsonValue(const QJsonValue &source) {
+    if (!source.isBool()) throw new ParseException("Error while trying to parse JSON value as boolean: not a boolean");
+    return source.toBool();
+}
+
+template <>
+QJsonValue toJsonValue(const bool &source) {
+    return QJsonValue(source);
+}
+
+// QString
+template <>
+QString fromJsonValue(const QJsonValue &source) {
+    if (!source.isString()) throw new ParseException("Error while trying to parse JSON value as string: not a string");
+    return source.toString();
+}
+
+template <>
+QJsonValue toJsonValue(const QString &source) {
+    return QJsonValue(source);
+}
+
+// Double
+template <>
+double fromJsonValue(const QJsonValue &source) {
+    if (!source.isDouble()) throw new ParseException("Error while trying to parse JSON value as integer: not a double");
+    return source.toDouble();
+}
+
+template <>
+QJsonValue toJsonValue(const double &source) {
+    return QJsonValue(source);
+}
+
+// QDateTime
+template <>
+QDateTime fromJsonValue(const QJsonValue &source) {
+    if (!source.isString()) throw new ParseException("Error while trying to parse JSON value as DateTime: not a string");
+    return QDateTime::fromString(source.toString(), Qt::ISODateWithMs);
+}
+
+template <>
+QJsonValue toJsonValue(const QDateTime &source) {
+    return QJsonValue(source.toString(Qt::ISODateWithMs));
+}
+
+// QUuid
+template <>
+QUuid fromJsonValue(const QJsonValue &source) {
+    if (!source.isString()) throw new ParseException("Error while trying to parse JSON value as QUuid: not a string");
+    return stringToUuid(source.toString());
+}
+
+template <>
+QJsonValue toJsonValue(const QUuid &source) {
+    return uuidToString(source);
+}
+
+} // NS Support
+} // NS Jellyfin