RFR: 7978: Add new metric prefixes

[Henrik Dafgård]

This PR adds the new metric prefixes quecto, ronto, ronna & quetta.

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Commit messages:
 - Add support for new metric prefixes

Changes: https://git.openjdk.org/jmc/pull/454/files
 Webrev: https://webrevs.openjdk.org/?repo=jmc&pr=454&range=00
  Issue: https://bugs.openjdk.org/browse/JMC-7978
  Stats: 56 lines in 5 files changed: 44 ins; 0 del; 12 mod
  Patch: https://git.openjdk.org/jmc/pull/454.diff
  Fetch: git fetch https://git.openjdk.org/jmc pull/454/head:pull/454

PR: https://git.openjdk.org/jmc/pull/454