[configuration] Separate Orphan Configs to New Categories Table

[skarya22]

Describe the bug

• Currently, to add a new Config section, you need to add a row to Config with no Parent - this is confusing
• We should create a new ConfigCategories table that relates to Config so that the Config entries can be assigned a Category
• An SQL patch should be made to move all existing orphaned Config rows to the new ConfigCategories table
• Add relevant column to Config to say what Category it is in