Add an error when the connection for the end calibration request fails

[Gold856]

Description

When the HTTP request to end calibration fails with a network error, the UI will show that the calibration failed, despite the fact the calibration may have actually succeeded on the server. This is most evident when you take hundreds of calibration images, and you need to wait a few minutes for the request to process. If the connection drops out for any reason (unstable connection due to use of the 2.4 GHz radio mode, or otherwise) users will now see a third error screen telling them they need to refresh the page to check the calibration manually.

This also changes the backend to broadcast out the calibration state when starting a calibration, which allows the state to be resynced if this error shows up.

Meta

Merge checklist:

• Pull Request title is short, imperative summary of proposed changes
• The description documents the what and why
• If this PR changes behavior or adds a feature, user documentation is updated
• If this PR touches photon-serde, all messages have been regenerated and hashes have not changed unexpectedly
• If this PR touches configuration, this is backwards compatible with settings back to v2024.3.1
• If this PR addresses a bug, a regression test for it is added

[Gold856]

Draft because if the connection comes back up, you click the OK button and start another calibration without refreshing, the snapshot number doesn't reset. Unsure of the best way to fix this (could do it client side or have the server send something).

[Gold856]

Changed the backend to always rebroadcast the calibration state when the start calibration button is clicked.