CR versions should be recognized as release candidates

[GeorgEchterling]

• [x] I have read the guidelines for submitting issues

🐛 Describe the bug

Hibernate uses CR as their marker for release candidates. RefreshVersions only recognizes RC as StabilityLevel.ReleaseCandidate. Because of this, the following configuration does not filter out Hibernate's release candidates as expected:

refreshVersions {
    rejectVersionIf {
        @Suppress("UnstableApiUsage")
        // Do not recommend upgrades from stable to unstable versions.
        candidate.stabilityLevel.isLessStableThan(current.stabilityLevel)
    }
}

⚠️ Current behavior

Versions such as 6.2.0.CR1and 6.2.0.CR2 are recognized as StabilityLevel.Stable.

✅ Expected behavior

Versions such as 6.2.0.CR1and 6.2.0.CR2 should be recognized as StabilityLevel.ReleaseCandidate.

💣 Steps to reproduce

• Add any stable Hibernate dependency in the 6.1.X line.
• Reject release candidates using rejectVersionIf.
• RefreshVersions will still recommend upgrades to 6.2.0.CR1and 6.2.0.CR2.