Add support for ODATA $filter, $select and $count on /scanConfigs (#84)

* Redo database interface to use model as input and output

This commit revisits the database interface such that each function takes
in and returns a VMClarity API model object. How the DB driver decides
to store these objects and process them efficently is the resposiblity
of the DB driver. We start with one DB driver, gorm, which converts the
model objects to GORM structs to save them.

api/openapi.yaml

@@ -362,8 +362,11 @@ paths:
       summary: Get all scan configs.
       parameters:
         - $ref: '#/components/parameters/odataFilter'
-        - $ref: '#/components/parameters/page'
-        - $ref: '#/components/parameters/pageSize'
+        - $ref: '#/components/parameters/odataSelect'
+        - $ref: '#/components/parameters/odataCount'
+        - $ref: '#/components/parameters/odataTop'
+        - $ref: '#/components/parameters/odataSkip'
+        - $ref: '#/components/parameters/odataExpand'
       responses:
         200:
           description: Success
@@ -404,6 +407,8 @@ paths:
       summary: Get the details for a scan config.
       parameters:
         - $ref: '#/components/parameters/scanConfigID'
+        - $ref: '#/components/parameters/odataSelect'
+        - $ref: '#/components/parameters/odataExpand'
       responses:
         200:
           description: Success
@@ -687,7 +692,7 @@ components:
     ScanConfigs:
       type: object
       properties:
-        total:
+        count:
           type: integer
           description: Total scan config count according to the given filters
           readOnly: true
@@ -698,8 +703,6 @@ components:
           items:
             $ref: '#/components/schemas/ScanConfig'
           readOnly: true
-      required:
-        - total
 
     ScanConfigData:
       type: object
@@ -1393,6 +1396,30 @@ components:
       schema:
         type: string
 
+    odataCount:
+      name: "$count"
+      in: query
+      schema:
+        type: boolean
+
+    odataTop:
+      name: "$top"
+      in: query
+      schema:
+        type: integer
+
+    odataSkip:
+      name: "$skip"
+      in: query
+      schema:
+        type: integer
+
+    odataExpand:
+      name: "$expand"
+      in: query
+      schema:
+        type: string
+
     scanID:
       name: scanID
       in: path