Attempting to load a wallet with an unknown descriptor causes a fatal error:

```
2022-09-06T01:51:06Z init message: Loading wallet…
2022-09-06T01:51:06Z [descriptor] Invalid descriptor: Can only have tr at top level: iostream error
2022-09-06T01:51:06Z [descriptor] Invalid descriptor: Can only have tr at top level: iostream error
2022-09-06T01:51:06Z [descriptor] Setting spkMan to active: id = 50e6032b4d1d62c020ebb6a4d0c8fafc6f01ea80f4d2a41c1a256086611636e9, type = legacy, internal = false
2022-09-06T01:51:06Z [descriptor] Setting spkMan to active: id = 7f709abbde61e8c253798375692bf41202e625ed74a65f9474d464be34fb2870, type = p2sh-segwit, internal = false
2022-09-06T01:51:06Z [descriptor] Setting spkMan to active: id = 2dc6c34099e0ca1235fc990a51042967ecbc8c8ac57062f964739cba2f451be8, type = bech32, internal = false
2022-09-06T01:51:06Z [descriptor] Setting spkMan to active: id = 8d3c63ea1ac9936e789713dc8bae857d328ff029ab9392e67c716752e9b11b0c, type = bech32m, internal = false
2022-09-06T01:51:06Z [descriptor] Releasing wallet
2022-09-06T01:51:06Z 

************************
EXCEPTION: St12out_of_range       
map::at       
bitcoin in Runaway exception       



************************
EXCEPTION: St12out_of_range       
map::at       
bitcoin in Runaway exception       

bitcoin-qt: ./checkqueue.h:204: CCheckQueue<CScriptCheck>::~CCheckQueue() [T = CScriptCheck]: Assertion `m_worker_threads.empty()' failed.
Aborted
```

> A fatal error occurred. Bitcoin Core can no longer continue safely and will quit.

To reproduce, a quick hack:

```c++
--- a/src/script/descriptor.cpp
+++ b/src/script/descriptor.cpp
@@ -1408,7 +1408,7 @@ std::unique_ptr<DescriptorImpl> ParseScript(uint32_t& key_exp_index, Span<const
         error = "Can only have addr() at top level";
         return nullptr;
     }
-    if (ctx == ParseScriptContext::TOP && Func("tr", expr)) {
+    if (ctx == ParseScriptContext::TOP && Func("trx", expr)) {
         auto arg = Expr(expr);
         auto internal_key = ParsePubkey(key_exp_index, arg, ParseScriptContext::P2TR, out, error);
         if (!internal_key) {
```
bool WriteTx(const CWalletTx& wtx);
    bool EraseTx(uint256 hash);
    bool WriteKeyMetadata(const CKeyMetadata& meta, const CPubKey& pubkey, const bool overwrite);
    bool WriteKey(const CPubKey& vchPubKey, const CPrivKey& vchPrivKey, const CKeyMetadata &keyMeta);
    bool WriteCryptedKey(const CPubKey& vchPubKey, const std::vector<unsigned char>& vchCryptedSecret, const CKeyMetadata &keyMeta);
    bool WriteMasterKey(unsigned int nID, const CMasterKey& kMasterKey);
    bool WriteCScript(const uint160& hash, const CScript& redeemScript);
    bool WriteWatchOnly(const CScript &script, const CKeyMetadata &keymeta);
    bool EraseWatchOnly(const CScript &script);
    bool WriteBestBlock(const CBlockLocator& locator);
    bool ReadBestBlock(CBlockLocator& locator);
    bool WriteOrderPosNext(int64_t nOrderPosNext);
    bool ReadPool(int64_t nPool, CKeyPool& keypool);
    bool WritePool(int64_t nPool, const CKeyPool& keypool);
    bool ErasePool(int64_t nPool);
    bool WriteMinVersion(int nVersion);
    bool WriteDescriptorKey(const uint256& desc_id, const CPubKey& pubkey, const CPrivKey& privkey);
    bool WriteCryptedDescriptorKey(const uint256& desc_id, const CPubKey& pubkey, const std::vector<unsigned char>& secret);
    bool WriteDescriptor(const uint256& desc_id, const WalletDescriptor& descriptor);
    bool WriteDescriptorDerivedCache(const CExtPubKey& xpub, const uint256& desc_id, uint32_t key_exp_index, uint32_t der_index);
    bool WriteDescriptorParentCache(const CExtPubKey& xpub, const uint256& desc_id, uint32_t key_exp_index);
    bool WriteDescriptorLastHardenedCache(const CExtPubKey& xpub, const uint256& desc_id, uint32_t key_exp_index);
    bool WriteDescriptorCacheItems(const uint256& desc_id, const DescriptorCache& cache);
    bool WriteLockedUTXO(const COutPoint& output);
    bool EraseLockedUTXO(const COutPoint& output);
    
    bool WriteDestData(const std::string &address, const std::string &key, const std::string &value);
    
    bool EraseDestData(const std::string &address, const std::string &key);
    bool WriteActiveScriptPubKeyMan(uint8_t type, const uint256& id, bool internal);