KEYPOD TESTING: Add unit testing to ensure over 90% coverage

[gjwgit]

Description

$ make coverage
COVERAGE
00:01 +1: All tests passed!                                                                                                                        

+---------------------------+-------+------+-------+
| file                      | lines | hits | cover |
+---------------------------+-------+------+-------+
| lib/main.dart             | 34    | 24   | 71    |
| lib/utils/is_desktop.dart | 2     | 0    | 0     |
| total                     | 36    | 24   | 67    |
+---------------------------+-------+------+-------+

The code coverage is too low: 67%. Expected at least 90%.
make: [support/flutter.mk:261: coverage] Error 1 (ignored)

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[gjwgit]

What makes this "in-progress"? If not likely to be looked at let's mode it to backlog for now.

[NinadBhat]

Moved to backlog.