added support for garmin track files (FIT)

[javisantana]

This PR adds support for FIT files, they are mostly generated by garmin GPS devices and are usually stored in the SDCARDS their products use.

I followed other file formats identify code so I hope everything is fine.

Thanks for this tool

[cgsecurity]

Can you share a .fit file sample ?

[javisantana]

You have one here https://github.com/dtcooper/python-fitparse/blob/master/tests/files/2013-02-06-12-11-14.fit

$ curl https://raw.githubusercontent.com/dtcooper/python-fitparse/master/tests/files/2013-02-06-12-11-14.fit > /tmp/test.fit

$ ./src/fidentify /tmp/test.fit
/tmp/test.fit: fit

[cgsecurity]

Can you check the code I have pushed in the main branch ? It fixes several problems.

[javisantana]

I've tested the recovery with current master and works as expected, thanks