unicode: strip additional rune ranges

[missinglink]

this PR removes two additional unicode ranges mentioned in https://github.com/pelias/api/issues/1574

• https://en.wikipedia.org/wiki/Regional_indicator_symbol (flags)
• https://en.wikipedia.org/wiki/Geometric_Shapes_Extended (colourful circles/squares)

[missinglink]

I feel like we should probably put in a space between two valid text blocks delimited by stripped elements?