FLEXOPTIX App: download ældre versioner

- Added Transceiver Firmware Updates for Flexbox 5, allowing users to view available transceiver firmware updates and install them directly from the app
- Fixed an issue where users could see a session error message after logging out instead of being returned to the start page
- Fixed an issue where clicking Retry could start multiple update downloads at the same time
- Fixed an issue where the optical power monitoring screen could get stuck showing live data after the connection stopped unexpectedly

- Fixed an issue where the app stopped detecting transceivers after a measurement error in the Optical Power Meter or OTDR (older Flexbox models only)
- Added a detail page for Flexbox 5 showing the serial number, firmware and bootloader versions, hardware revision, and network addresses

- improved OTDR error handling to keep the last successful measurement visible when an error occurs
- improved error messages in Serial Number Lookup for unsupported products
- added support for displaying all supported Rx wavelengths in the transceiver information panel on Flexbox 5
- fixed an issue where some app updates were not installed correctly