[com.google.fonts/check/interpolation_issues] forgot to display glyph name

[simoncozens]

Observed behaviour

As @colinmford has colourfully pointed out, the new updates to the interpolation_issues check (underweight, overweight, kink, etc.) do not report the name of the glyph in which the issue was found.

Expected behaviour

The error message should include the glyph name.

[felipesanches]

thanks, @simoncozens