As part of this ticket, we will:

• Parse latestFCV from MONGO_VERSION, which is parsed from the git tag.
• Set lastRapid as the highest version in featureCompatibilityVersions that is less than latestFCV.
• Set lastMajor as the highest version in majorReleases that is less than latestFCV.

We will create a GenericFCV enum that has these values set to their corresponding FCV constant. In addition, the FCV constants enum should only generate FCVs from lastMajor onwards.