fix(cli): JSON output spells date and sequence strategies without their hyphens #1292

Left out of #1259 on purpose. check --json and release --json report bump_type as calvershortseq for a package on calver-short-seq, and why --json reports strategy the same way, because both build the name from Debug lowercased. Those values are not valid in the config and do not match what doctor prints since #1259. Use VersioningStrategy's Display, which matches the config spelling. Decided to ship as a fix, not a major.