rpc: Don't translate warning messages

But keep translating them in the GUI.
This - necessarily - requires duplication of a few messages.
Alternative take on #7134, that keeps the translations from being wiped.

Also document GetWarnings() input argument.

Fixes #5895.

src/main.cpp

@@ -3979,29 +3979,34 @@ std::string GetWarnings(const std::string& strFor)
     int nPriority = 0;
     string strStatusBar;
     string strRPC;
+    string strGUI;
 
-    if (!CLIENT_VERSION_IS_RELEASE)
-        strStatusBar = _("This is a pre-release test build - use at your own risk - do not use for mining or merchant applications");
+    if (!CLIENT_VERSION_IS_RELEASE) {
+        strStatusBar = "This is a pre-release test build - use at your own risk - do not use for mining or merchant applications";
+        strGUI = _("This is a pre-release test build - use at your own risk - do not use for mining or merchant applications");
+    }
 
     if (GetBoolArg("-testsafemode", DEFAULT_TESTSAFEMODE))
-        strStatusBar = strRPC = "testsafemode enabled";
+        strStatusBar = strRPC = strGUI = "testsafemode enabled";
 
     // Misc warnings like out of disk space and clock is wrong
     if (strMiscWarning != "")
     {
         nPriority = 1000;
-        strStatusBar = strMiscWarning;
+        strStatusBar = strGUI = strMiscWarning;
     }
 
     if (fLargeWorkForkFound)
     {
         nPriority = 2000;
-        strStatusBar = strRPC = _("Warning: The network does not appear to fully agree! Some miners appear to be experiencing issues.");
+        strStatusBar = strRPC = "Warning: The network does not appear to fully agree! Some miners appear to be experiencing issues.";
+        strGUI = _("Warning: The network does not appear to fully agree! Some miners appear to be experiencing issues.");
     }
     else if (fLargeWorkInvalidChainFound)
     {
         nPriority = 2000;
-        strStatusBar = strRPC = _("Warning: We do not appear to fully agree with our peers! You may need to upgrade, or other nodes may need to upgrade.");
+        strStatusBar = strRPC = "Warning: We do not appear to fully agree with our peers! You may need to upgrade, or other nodes may need to upgrade.";
+        strGUI = _("Warning: We do not appear to fully agree with our peers! You may need to upgrade, or other nodes may need to upgrade.");
     }
 
     // Alerts
@@ -4013,12 +4018,14 @@ std::string GetWarnings(const std::string& strFor)
             if (alert.AppliesToMe() && alert.nPriority > nPriority)
             {
                 nPriority = alert.nPriority;
-                strStatusBar = alert.strStatusBar;
+                strStatusBar = strGUI = alert.strStatusBar;
             }
         }
     }
 
-    if (strFor == "statusbar")
+    if (strFor == "gui")
+        return strGUI;
+    else if (strFor == "statusbar")
         return strStatusBar;
     else if (strFor == "rpc")
         return strRPC;

src/main.h

@@ -206,7 +206,13 @@ void ThreadScriptCheck();
 void PartitionCheck(bool (*initialDownloadCheck)(), CCriticalSection& cs, const CBlockIndex *const &bestHeader, int64_t nPowTargetSpacing);
 /** Check whether we are doing an initial block download (synchronizing from disk or network) */
 bool IsInitialBlockDownload();
-/** Format a string that describes several potential problems detected by the core */
+/** Format a string that describes several potential problems detected by the core.
+ * strFor can have three values:
+ * - "rpc": get critical warnings, which should put the client in safe mode if non-empty
+ * - "statusbar": get all warnings
+ * - "gui": get all warnings, translated (where possible) for GUI
+ * This function only returns the highest priority warning of the set selected by strFor.
+ */
 std::string GetWarnings(const std::string& strFor);
 /** Retrieve a transaction (from memory pool, or from disk, if possible) */
 bool GetTransaction(const uint256 &hash, CTransaction &tx, const Consensus::Params& params, uint256 &hashBlock, bool fAllowSlow = false);

src/qt/clientmodel.cpp

@@ -158,7 +158,7 @@ enum BlockSource ClientModel::getBlockSource() const
 
 QString ClientModel::getStatusBarWarnings() const
 {
-    return QString::fromStdString(GetWarnings("statusbar"));
+    return QString::fromStdString(GetWarnings("gui"));
 }
 
 OptionsModel *ClientModel::getOptionsModel()