Split grammar (#15)

* Move grammar parsers to entity classes

* Fix includes

* Fix Entity5 test

* Small detail

* Fix unknown keys entities

* Persistent grammar objects

* Fix grammar

* Grammar from variable

js/entity/EnumDisplayValueEntity.js

@@ -1,5 +1,12 @@
 import EnumEntity from "./EnumEntity.js"
+import Grammar from "../serialization/Grammar.js"
+import Parsimmon from "parsimmon"
 
 export default class EnumDisplayValueEntity extends EnumEntity {
 
+    static grammar = this.createGrammar()
+
+    static createGrammar() {
+        return Parsimmon.regex(Grammar.Regex.InsideString).map(v => new this(v))
+    }
 }