Remove variation selectors from sigil

The choice of whether to render a character as emoji style or text
style is properly a font and typesetting decision, not a character
encoding one. Altho Unicode provides variation selectors for indicating
a preference in plain text, these selectors should not be given formal
significance. To be clear that the canonical encoding for the sigil is
`<U+26E9,U+1F4F0>`, remove them across the board.