refactor: rename info() to header() (#6138)

This change renames all the `info()` functions to `header()`, since they return `LedgerHeader` structs. It also renames the underlying variables from `info_` to `header_`.

src/test/jtx/impl/Env.cpp

@@ -67,7 +67,8 @@ Env::AppBundle::AppBundle(
     app->logs().threshold(thresh);
     if (!app->setup({}))
         Throw<std::runtime_error>("Env::AppBundle: setup failed");
-    timeKeeper->set(app->getLedgerMaster().getClosedLedger()->info().closeTime);
+    timeKeeper->set(
+        app->getLedgerMaster().getClosedLedger()->header().closeTime);
     app->start(false /*don't start timers*/);
     thread = std::thread([&]() { app->run(); });
 
@@ -107,7 +108,7 @@ Env::close(
     // Round up to next distinguishable value
     using namespace std::chrono_literals;
     bool res = true;
-    closeTime += closed()->info().closeTimeResolution - 1s;
+    closeTime += closed()->header().closeTimeResolution - 1s;
     timeKeeper().set(closeTime);
     // Go through the rpc interface unless we need to simulate
     // a specific consensus delay.
@@ -130,7 +131,7 @@ Env::close(
             res = false;
         }
     }
-    timeKeeper().set(closed()->info().closeTime);
+    timeKeeper().set(closed()->header().closeTime);
     return res;
 }
 

src/test/jtx/impl/Oracle.cpp

@@ -216,7 +216,7 @@ Oracle::set(UpdateArg const& arg)
     else
         jv[jss::LastUpdateTime] = to_string(
             duration_cast<seconds>(
-                env_.current()->info().closeTime.time_since_epoch())
+                env_.current()->header().closeTime.time_since_epoch())
                 .count() +
             epoch_offset.count());
     Json::Value dataSeries(Json::arrayValue);