<!-- Describe the issue -->

When our chainstate activation sequence fails and we're running the GUI, we ask the user via a question box whether or not they'd like to re-run the sequence with `fReindex = true`. Fun fact: despite the fact that this sequence is wrapped in a while loop, we only run it twice at most.

https://github.com/bitcoin/bitcoin/blob/7ecb309c4ed1bb9ae6b9a12cbb4f083328edc125/src/init.cpp#L1539-L1556

If they answer yes, the sequence will always fail, because a chainstate will have already been initialized in the original run and `InitializeChainstate` will throw a `std::logic_error`:

https://github.com/bitcoin/bitcoin/blob/7ecb309c4ed1bb9ae6b9a12cbb4f083328edc125/src/validation.cpp#L4573-L4594

This always reproduces. To reproduce:
```
gdb ./src/qt/bitcoin-qt
(gdb) b InitializeChainstate
(gdb) # add breakpoint for the "if (!fLoaded && !ShutdownRequested()) {" line
(gdb) r  # should stop at the breakpoint for InitializeChainstate
(gdb) c  # to advance to the breakpoint for the "if (!fLoaded && !ShutdownRequested()) {" line
(gdb) set fLoaded=false
(gdb) c  # should stop at the breakpoint for InitializeChainstate
(gdb) n  # step through InitializeChainstate to see that it throws
```

We expect the re-run of the chainstate activation sequence to not always fail.

{
        LOCK(::cs_main);
        size_t coins_in_active{0};
        size_t coins_in_background{0};
        size_t coins_missing_from_background{0};
        for (CChainState* chainstate : chainman.GetAll()) {
            BOOST_TEST_MESSAGE("Checking coins in " << chainstate->ToString());
            CCoinsViewCache& coinscache = chainstate->CoinsTip();
            bool is_background = chainstate != &chainman.ActiveChainstate();
            for (CTransactionRef& txn : m_coinbase_txns) {
                COutPoint op{txn->GetHash(), 0};
                if (coinscache.HaveCoin(op)) {
                    (is_background ? coins_in_background : coins_in_active)++;
                } else if (is_background) {
                    coins_missing_from_background++;
                }
            }
        }
        BOOST_CHECK_EQUAL(coins_in_active, initial_total_coins + new_coins);
        BOOST_CHECK_EQUAL(coins_in_background, initial_total_coins);
        BOOST_CHECK_EQUAL(coins_missing_from_background, new_coins);
    }
    
    BOOST_REQUIRE(!CreateAndActivateUTXOSnapshot(m_node, m_path_root));
    
    BOOST_CHECK_EQUAL(
        *chainman.ActiveChainstate().m_from_snapshot_blockhash,
        loaded_snapshot_blockhash);
}
BOOST_FIXTURE_TEST_CASE(chainstatemanager_loadblockindex, TestChain100Setup)