UI: Consolidate Host, Platform, Strata Interfaces into Base Layer

[dimak1]

Currently, for Examiners App is only extending the Base Layer. So to utilize application interfaces from Host, Platform, Strata, they had to be manually copied over to examiners-web-app. This creates duplication and lack of consistency if any of those interfaces is changed in the original respective application.

So the proposed tasks are:

• Move Host, Platform, Strata Interfaces to Base Layer
• Remove duplicate interfaces from Examiner app
• Use Host, Platform, Strata from the Base Layer in Examiner app