<!-- 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.

{
    ChainstateManager& chainman = *Assert(m_node.chainman);
    uint256 curr_tip = ::g_best_block;
    
    
    mineBlocks(10);
    
    BOOST_CHECK(::g_best_block != curr_tip);
    BOOST_REQUIRE(CreateAndActivateUTXOSnapshot(m_node, m_path_root));
    
    BOOST_CHECK(chainman.IsSnapshotActive());
    curr_tip = ::g_best_block;
    
    mineBlocks(1);  
    
    BOOST_CHECK(::g_best_block != curr_tip);
    curr_tip = ::g_best_block;
    BOOST_CHECK_EQUAL(chainman.GetAll().size(), 2);
    CChainState& background_cs{*[&] {
        for (CChainState* cs : chainman.GetAll()) {
            if (cs != &chainman.ActiveChainstate()) {
                return cs;
            }
        }
        assert(false);
    }()};