[BACKLOG-290] REST: Overhaul the data-access APIs

-backed out changes to plugin.spring.xml
-workaround for not having spring beans for new resources
-cleanup and code formatting update for any touched files
-fixed unused import issues
-restored existing data-access REST class methods from an API and removed their annotations if the @Path is now managed by a new Resource
-standardized the REST @Path across all datasource types (eg /data-access/api/datasource/analysis)