Realign naming of configuration settings

[BernieWhite]

Configuration setting name should only use caps to align to how environment variables are set. On Linux environment variables are case-sensitive. As a result, environment variables are commonly expressed with all caps.

To reduce confusion when setting configuration via environment variables all configuration names should be updated to use only caps. This will be a breaking change and will affect the following configuration options:

• Azure_AKSMinimumVersion
• Azure_AKSNodeMinimumMaxPods
• Azure_AllowedRegions
• Azure_MinimumCertificateLifetime

Renamed configuration options will be:

• [x] AZURE_AKS_CLUSTER_MINIMUM_VERSION instead of Azure_AKSMinimumVersion
• [x] AZURE_AKS_POOL_MINIMUM_MAXPODS instead of Azure_AKSNodeMinimumMaxPods
• [x] AZURE_RESOURCE_ALLOWED_LOCATIONS instead of Azure_AllowedRegions
• [x] AZURE_APIM_MINIMUM_CERTIFICATE_LIFETIME instead of Azure_MinimumCertificateLifetime