Completely remove oes::core::Format class and all usages

Type of change

• Bug Fix
• Feature

Does this introduce a change in the core logic?

• [No]

Does this introduce a change in the cloud provider implementation, if so which cloud?

• AWS
• Azure
• GCP
• IBM

Updates description?

This MR completely removes oes::core::Format class and all usages (accordingly to decisions in the #53 (closed))