Track coil icon and navigation tab

[v-malheiro]

I have done some tests on the lastest changes in the main branch and found interesting relations that didn't exist before:

• The navigation tab can't be opened anymore if you don't complete the registration process;

• If the track coil icon is already activated and you click on it, the track coil icon will be deativated (as expected) and the new probe icon will automatically be activated. In the same way, if you activate the track coil, the probe icon will be deactivated;
  

• When the track coil is deactivated, the target mode will be too. Then, if you activate track coil, the target mode will be clickable but will stay with a grey background (instead of orange, as it was supposed to be). Now, if you activate and deactivate the target mode at least once, then it will have an orange background;