Simulated Interface fw version is out of date

[peterhollender]

The simulated interface has a hard-coded configuration and firmware versions. This currently kicks out a firmware update required warning in the test app. We should:

1. Change the simulated interface to default to dynamically retrieving the latest fw versions for its user config and firmware version responses.
2. Add arguments that allow us to construct one with a specific fw version
3. Implement simulated firmware updates that change the version as if the hardware is being updated.
4. Wire these functions up in openlifu-test-app for use