Add tests for unicode-range

[bartveneman]

• Should not be parsed as dimensions

@font-face {
 font-display: swap;
 font-family: Fira Sans;
 font-style: italic;
 font-weight: 200;
 src:
  url(/assets/fonts/fira-sans-cyrillic-ext-200-italic-e2d54a21d31645a6a5142dba15d29ed4.woff2) format("woff2"),
  url(/assets/fonts/fira-sans-cyrillic-ext-200-italic-a0369dc440f472516e4ea701efd0a5b9.woff) format("woff");
 unicode-range: u+0460-052f, u+1c80-1c8a, u+20b4, u+2de0-2dff, u+a640-a69f, u+fe2e-fe2f;
}