CRUD operations for Posts

- added all CRUD operations for Post model
- add() also creates POST_BY_MEMBER and POST_FROM_NETWORK edges
- delete() also deletes associated edges
- delete() currently does not reallocate node/edge indices after deleting
- will write the data to the db.json file and global.db.nodes

server/db/model/network.js

@@ -24,6 +24,15 @@ export default class Network  {
         return global.db.nodes[index]
     }
 
+    getByAbbreviation(abbreviation) {
+        for(let i=this.indices[0]; i<this.indices[1]; i++) {
+            if(global.db.nodes[i].abbreviation === abbreviation) {
+                return global.db.nodes[i]
+            }
+        }
+        return null
+    }
+
     save(n) {
         let id = `${this.prefix}-${n.id}`
         let result = this.schema.safeParse(n)