Added EBS IO2 volumeType support to Managed NodeGroup

[bhowmick-sumit]

Feature: #7905

Description

• Added EBS IO2 type to the list of supported volume types in NodeGroup
• Validation for minimum and maximum IOPS values supported by EBS IO2 (100-256000) was added.
• Default IOPS value for the IO2 volume type is 100 IOPS(minimum supported value).

Checklist

• [x] Added tests that cover your change (if possible)
• [ ] Added/modified documentation as required (such as the README.md, or the userdocs directory)
• [x] Manually tested
• [x] Made sure the title of the PR is a good description that can go into the release notes
• [ ] (Core team) Added labels for change area (e.g. area/nodegroup) and kind (e.g. kind/improvement)

BONUS POINTS checklist: complete for good vibes and maybe prizes?! :exploding_head:

• [ ] Backfilled missing tests for code in same general area :tada:
• [ ] Refactored something and made the world a better place :star2: