scripted-diff: Rename m_is_loaded -> m_load_tried

m_is_loaded/IsLoaded() doesn't actually indicate whether or not the
mempool was successfully, loaded, but rather if a load has been
attempted and did not result in a catastrophic ShutdownRequested.

-BEGIN VERIFY SCRIPT-
find_regex="\bm_is_loaded\b" \
    && git grep -l -E "$find_regex" \
        | xargs sed -i -E "s@$find_regex@m_load_tried@g"

find_regex="\bIsLoaded\b" \
    && git grep -l -E "$find_regex" \
        | xargs sed -i -E "s@$find_regex@GetLoadTried@g"

find_regex="\bSetIsLoaded\b" \
    && git grep -l -E "$find_regex" \
        | xargs sed -i -E "s@$find_regex@SetLoadTried@g"
-END VERIFY SCRIPT-

src/txmempool.cpp

@@ -1210,14 +1210,14 @@ void CTxMemPool::GetTransactionAncestry(const uint256& txid, size_t& ancestors,
     }
 }
 
-bool CTxMemPool::IsLoaded() const
+bool CTxMemPool::GetLoadTried() const
 {
     LOCK(cs);
-    return m_is_loaded;
+    return m_load_tried;
 }
 
-void CTxMemPool::SetIsLoaded(bool loaded)
+void CTxMemPool::SetLoadTried(bool loaded)
 {
     LOCK(cs);
-    m_is_loaded = loaded;
+    m_load_tried = loaded;
 }