Master-Key only queried once, not after a resave of the Keepass file

### How to reproduce?
- Query a secret (MasterKey is required)
- Save the database file from within the app
- Query the secret again
- An exception is thrown
- To access the database again you have to restart the powershell session or use Unlock-SecretVault

```Powershell
C:\> get-secret hubba

Keepass Master Password
Enter the Keepass Master password for: *****\KeepassDatabase.kdbx
Password for user Keepass Master Password: **********

UserName Password
-------- --------
user System.Security.SecureString

C:\> # Save the file from the app
C:\> get-secret hubba
WARNING: [14:18:19][Test-SecretVault] Database file on disk has changed, starting a new connection
WARNING: [14:18:19][Get-SecretInfo] There appears to be an issue with the vault (Test-SecretVault returned false)
Get-Secret: A valid password is required to access the Microsoft.PowerShell.SecretStore vault.
Use the Unlock-SecretStore cmdlet to provide the required password to access the store.
Get-Secret: The secret hubba was not found.
C:\>
```

## Expected behavior
Either use the cached password again or ask for it a second time.

Start with the Test-SecretVault and Get-Secret flow shown in the reproduction, especially the handling after the database file changes. Reproduce the sequence in a PowerShell session; done means querying the secret after saving the Keepass file succeeds by reusing the cached password or prompting for it again.

Written by the indexing model from the issue text.