Improve cluster-config validations

[vishalbollu]

Version

v0.12 (and older)

Description

Update the following validations:

• cluster name
  • comply with eks and eksctl requirements (if there are any)
  • needs to be safe for including in file names
• s3 bucket
  • comply s3 bucket naming requirements
  • default is based on cluster name
• log group (default is based on log group)
  • comply with aws cloudwatch log group naming requirements
  • default is based on log group