Refactor PollHandler

Refactor PollHandler to make it more reliable. This ended up with much more code than I expected as the original intent was just to stop a crash when switching rooms.
- Using a event string was flaky, changing to using an event reference is more reliable.
- Since we're only creating them from NeoChatRoom there is no need to to be able to set properties from QML so only read properties.
- Pass from the MessageEventModel rather than an invokable method.
- Create a basic test suite
- Create properties in PollHandler to remove the need to use content in PollDelegate, this means content is no longer a required role.

autotests/pollhandlertest.cpp

@@ -0,0 +1,70 @@
+// SPDX-FileCopyrightText: 2023 James Graham <james.h.graham@protonmail.com>
+// SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-only OR LicenseRef-KDE-Accepted-GPL
+
+#include <QObject>
+#include <QSignalSpy>
+#include <QTest>
+
+#include <Quotient/connection.h>
+#include <Quotient/quotient_common.h>
+#include <Quotient/syncdata.h>
+
+#include "events/pollevent.h"
+#include "pollhandler.h"
+#include "testutils.h"
+
+using namespace Quotient;
+
+class PollHandlerTest : public QObject
+{
+    Q_OBJECT
+
+private:
+    Connection *connection = nullptr;
+    TestUtils::TestRoom *room = nullptr;
+
+private Q_SLOTS:
+    void initTestCase();
+    void nullObject();
+    void poll();
+};
+
+void PollHandlerTest::initTestCase()
+{
+    connection = Connection::makeMockConnection(QStringLiteral("@bob:kde.org"));
+    room = new TestUtils::TestRoom(connection, QStringLiteral("#myroom:kde.org"), "test-pollhandlerstart-sync.json"_ls);
+}
+
+// Basically don't crash.
+void PollHandlerTest::nullObject()
+{
+    auto pollHandler = PollHandler();
+
+    QCOMPARE(pollHandler.hasEnded(), false);
+    QCOMPARE(pollHandler.answerCount(), 0);
+    QCOMPARE(pollHandler.question(), QString());
+    QCOMPARE(pollHandler.options(), QJsonArray());
+    QCOMPARE(pollHandler.answers(), QJsonObject());
+    QCOMPARE(pollHandler.counts(), QJsonObject());
+    QCOMPARE(pollHandler.kind(), QString());
+}
+
+void PollHandlerTest::poll()
+{
+    auto startEvent = eventCast<const PollStartEvent>(room->messageEvents().at(0).get());
+    auto pollHandler = PollHandler(room, startEvent);
+
+    auto options = QJsonArray{QJsonObject{{"id"_ls, "option1"_ls}, {"org.matrix.msc1767.text"_ls, "option1"_ls}},
+                              QJsonObject{{"id"_ls, "option2"_ls}, {"org.matrix.msc1767.text"_ls, "option2"_ls}}};
+
+    QCOMPARE(pollHandler.hasEnded(), false);
+    QCOMPARE(pollHandler.answerCount(), 0);
+    QCOMPARE(pollHandler.question(), QStringLiteral("test"));
+    QCOMPARE(pollHandler.options(), options);
+    QCOMPARE(pollHandler.answers(), QJsonObject());
+    QCOMPARE(pollHandler.counts(), QJsonObject());
+    QCOMPARE(pollHandler.kind(), QStringLiteral("org.matrix.msc3381.poll.disclosed"));
+}
+
+QTEST_GUILESS_MAIN(PollHandlerTest)
+#include "pollhandlertest.moc"