Add visibility of firmware version check & update to app (as in LabraScope)

[mi-hol]

Is your feature request related to a problem? Please describe.
devices with old firmware are neither identified nor updated

Describe the solution you'd like
Handle it automatically at start-up like in LabraScope

[EspoTek]

The regular software already automatically detects and updates (or downgrades, or changes variant of) the firmware automatically.

It just doesn't give a prompt like this.

[mi-hol]

The regular software already automatically detects and updates (or downgrades, or changes variant of) the firmware automatically

That seems not to work correctly then. I used the specific device (Backer's Edition Batch2) since about a year. I verified with a second device (from same batch owned by a friend) with the same result.

[mi-hol]

@EspoTek wiki currently only mentions how dfu-programmer can be used to flash firmware.
https://github.com/espotek-org/Labrador/wiki/Troubleshooting-Guide#windows

triggered by "changes variant of the firmware" made me re-read above wiki and I noticed

*_01 is mentioned for Windows and *_02 for UNIX-based OSes.

Are there 2 different "types" of Labrador firmware required?

"The regular software already automatically detects and updates (or downgrades, or changes variant of) the firmware automatically" should be added because it is an important fact.

[mi-hol]

note to myself, #260 (comment) mentions this too but visibility to user is missing and has already caused confusions to contributors.

from a UNIX Labrador.log file:

CHECKING CONNECTION!
Entering unixUsbDriver::usbInit
Libusb context initialised
Device found!!
KERNEL DRIVER INACTIVE
Interface claimed!
Connected
BOARD IS RUNNING FIRMWARE VERSION 0x0007
EXPECTING FIRMWARE VERSION 0x0007
FIRMWARE VARIANT = 0x02
EXPECTED VARIANT = 0x02
Connecting now!