API: Reviewed changes for API priority control

Review of #4313
- Made constructor changes while reviewing some classes.
- Updated API examples for consistency.
- Tweaked formatting for some array changes.
- Simplified added tests.
- Tweaked chapter/page repo priority handling to be simpler.

Performed manual API endpoint testing of page/chapter create/update.

dev/api/requests/chapters-create.json

@@ -2,10 +2,9 @@
   "book_id": 1,
   "name": "My fantastic new chapter",
   "description": "This is a great new chapter that I've created via the API",
+  "priority": 15,
   "tags": [
     {"name": "Category", "value": "Top Content"},
     {"name": "Rating", "value": "Highest"}
-  ],
-  "priority": 15
-}
+  ]
 }

dev/api/requests/chapters-update.json

@@ -2,9 +2,9 @@
   "book_id": 1,
   "name": "My fantastic updated chapter",
   "description": "This is an updated chapter that I've altered via the API",
+  "priority": 16,
   "tags": [
     {"name": "Category", "value": "Kinda Good Content"},
     {"name": "Rating", "value": "Medium"}
-  ],
-  "priority": 15
+  ]
 }

dev/api/requests/pages-create.json

@@ -2,9 +2,9 @@
 	"book_id": 1,
 	"name": "My API Page",
 	"html": "<p>my new API page</p>",
+	"priority": 15,
 	"tags": [
 		{"name": "Category", "value": "Not Bad Content"},
 		{"name": "Rating", "value": "Average"}
-	],
-	"priority": 15
+	]
 }

dev/api/requests/pages-update.json

@@ -2,9 +2,9 @@
 	"chapter_id": 1,
 	"name": "My updated API Page",
 	"html": "<p>my new API page - Updated</p>",
+	"priority": 16,
 	"tags": [
 		{"name": "Category", "value": "API Examples"},
 		{"name": "Rating", "value": "Alright"}
-	],
-	"priority": 15
+	]
 }

dev/api/responses/chapters-create.json

@@ -4,7 +4,7 @@
   "slug": "my-fantastic-new-chapter",
   "name": "My fantastic new chapter",
   "description": "This is a great new chapter that I've created via the API",
-  "priority": 6,
+  "priority": 15,
   "created_by": 1,
   "updated_by": 1,
   "owned_by": 1,

dev/api/responses/chapters-update.json

@@ -4,7 +4,7 @@
   "slug": "my-fantastic-updated-chapter",
   "name": "My fantastic updated chapter",
   "description": "This is an updated chapter that I've altered via the API",
-  "priority": 7,
+  "priority": 16,
   "created_at": "2020-05-22T23:03:35.000000Z",
   "updated_at": "2020-05-22T23:07:20.000000Z",
   "created_by": 1,

dev/api/responses/pages-create.json

@@ -6,7 +6,7 @@
 	"slug": "my-api-page",
 	"html": "<p id=\"bkmrk-my-new-api-page\">my new API page</p>",
 	"raw_html": "<p id=\"bkmrk-my-new-api-page\">my new API page</p>",
-	"priority": 14,
+	"priority": 15,
 	"created_at": "2020-11-28T15:01:39.000000Z",
 	"updated_at": "2020-11-28T15:01:39.000000Z",
 	"created_by": {