The matched character ranges within the original candidate, ordered by
start. Empty when FuzzyScore.score is 0.
Normalised match strength in [0, 1]: 1 is an exact (case-insensitive)
match and 0 means no match. Intermediate values are tiered so that a
prefix match always outranks a substring match, which outranks a
subsequence or typo match.
The result of scoring a query against a single candidate.