Removing device catalog

[nivemaham]

• Removes the use of embedded device-catalog and related classes.
• Uses source-type definitions served from MP as the SourceCatalogue
• Removes dependency of rest-api schema
• Uses in-built POJO classes for responses
• Changes the REST endpoints to align with the APIs proposed at #63 and #42
• Removes static classes and methods
• Uses Service classes that can be injected
• Removes stale test codes
• Removes unnecessary methods that can now be served from MP
• Integration tests to use sample data from MP
• Introduces SourceMonitorService that can query records from SourceMonitorStatistics
• Removes inbuilt classes for MP responses and uses MP distribution.
• Updated endpoint tests corresponding to latest apis