Add columns to backup storage location to indicate which one is the default

[carlisia]

• to indicate which one is the default

Edited on 11/18:

• to show last validated time -> this was already done
• to show validation frequency -> opened a separate issue for this: Add a column to BSL to indicate the validation frequency #3098
• to add a default column for VSL -> Add columns to backup storage location to indicate which one is the default