Add ProjectZomboid log base classes

ProjectZomboidLog (abstract): extends AnalysableLog, implements
DetectableLogInterface. Centralises the PZ timestamp format
('d-m-y H:i:s.v') and UTC default timezone, plus a makePatternParser()
helper so concrete subclasses only specify their line regex and capture
group names. ProjectZomboidEventLog (abstract): marker base for the ten
single-line structured PZ logs, distinct from the multi-line
ProjectZomboidServerLog. Concrete subclasses follow.

src/Log/ProjectZomboid/ProjectZomboidEventLog.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace IndifferentKetchup\Codex\Log\ProjectZomboid;
+
+/**
+ * Marker base for ProjectZomboid logs whose entries are strictly one line
+ * each (the ten structured event files: admin, BurdJournals, chat,
+ * ClientActionLog, cmd, item, map, PerkLog, pvp, user). Distinct from
+ * ProjectZomboidServerLog, which permits multi-line entries
+ * (DebugLog-server stack traces).
+ */
+abstract class ProjectZomboidEventLog extends ProjectZomboidLog
+{
+}