accounts: ledger and HD review fixes

- Handle a data race where a Ledger drops between list and open
- Prolong Ledger tx confirmation window to 30 days from 1 minute
- Simplify Ledger chainid-signature calculation and validation
- Simplify Ledger USB APDU request chunking algorithm
- Silence keystore account cache notifications for manual actions
- Only enable self derivations if wallet open succeeds

accounts/keystore/account_cache.go

@@ -113,11 +113,6 @@ func (ac *accountCache) add(newAccount accounts.Account) {
 	copy(ac.all[i+1:], ac.all[i:])
 	ac.all[i] = newAccount
 	ac.byAddr[newAccount.Address] = append(ac.byAddr[newAccount.Address], newAccount)
-
-	select {
-	case ac.notify <- struct{}{}:
-	default:
-	}
 }
 
 // note: removed needs to be unique here (i.e. both File and Address must be set).
@@ -131,10 +126,6 @@ func (ac *accountCache) delete(removed accounts.Account) {
 	} else {
 		ac.byAddr[removed.Address] = ba
 	}
-	select {
-	case ac.notify <- struct{}{}:
-	default:
-	}
 }
 
 func removeAccount(slice []accounts.Account, elem accounts.Account) []accounts.Account {