Log Browser: add human readable string for Events 85, 86, 87

[rmackay9]

The Log Browser displays little red tabs at the top for "Events" but it is missing the human readible text for events added in the last year.

The list of events can be found in the flight code here and I'm sure the three below are missing (maybe there are more) EK3_SOURCES_SET_TO_PRIMARY = 85, EK3_SOURCES_SET_TO_SECONDARY = 86, EK3_SOURCES_SET_TO_TERTIARY = 87,