Fixed retrieval of character variables to include local traits and central traits observed only in local environments

GCP-10522

Reviewer: Mae Turiana
Fixed retrieval of numeric variables to include local traits and central traits observed only in local environments

GCP-10522

Reviewer: Mae Turiana
Fixed retrieval of categorical variables to include local traits and central traits observed only in local environments

GCP-10522

Reviewer: Mae Turiana
Code Cleanup: Use Collections.isEmpty() to check whether list is empty or not

GCP-10552

Reviewer: Mae Turiana