feat: Recover from fallback writer state (#3000)

Add a timer and new `FallbackRecovery` state to try to recover from
`Fallback` writer state every hour.
Fixes #2997

src/etl/WriterState.cpp

@@ -69,6 +69,7 @@ void
 WriterState::setWriterDecidingFallback()
 {
     systemState_->isWriterDecidingFallback = true;
+    isFallbackRecovery_ = false;
 }
 
 bool
@@ -77,6 +78,21 @@ WriterState::isFallback() const
     return systemState_->isWriterDecidingFallback;
 }
 
+bool
+WriterState::isFallbackRecovery() const
+{
+    return isFallbackRecovery_;
+}
+
+void
+WriterState::setFallbackRecovery(bool newValue)
+{
+    if (newValue) {
+        systemState_->isWriterDecidingFallback = false;
+    }
+    isFallbackRecovery_ = newValue;
+}
+
 bool
 WriterState::isEtlStarted() const
 {