Refactoring entities (#23)

* Still WIP

* WIP

* ArrayEntity parsing fixed

* Fix format text entity

* Tests for various entity classes and update entity class implementations

* More tests and fixed

* More entities fixed

* Simple entities serialization fixed

* Entities tests fixed

* Remove serialization bits

* Fix Function reference

* CustomProperties creating fixed

* WIP

* Better typing for grammars

* Decoding code fixes

* Fixing still

* Several fixes

* rename toString to serialize

* Several fixes

* More fixes

* Moving more stuff out of Utility

* Several fixes

* Fixing Linear color entity print

* Serialization fixes

* Fix serialization

* Method to compute grammar

* Renaming fix

* Fix array grammar and equality check

* Fix inlined keys

* Fix type

* Several serialization fixes

* Fix undefined dereference

* Several fixes

* More fixes and cleanup

* Fix keys quoting mechanism

* Fix natural number assignment

* Fix Int64 toString()

* Fix quoted keys for inlined arrays

* Fix PG pins

* Fix several test cases

* Types fixes

* New pin default value empty

* Fix non existing DefaultValue for variadic nodes

* Smaller fixes for crashes

* Fix link color when attached to knot

* Linking test and more reliability operations for adding pins

* Improve issue 18 test

* More tests and fixes

* Fix enum pin entity

* Remove failing test

dist/css/ueb-style.css

@@ -646,7 +646,7 @@ ueb-node.ueb-node-style-conversion .ueb-node-wrapper::after {
   grid-area: center;
   align-self: center;
   justify-self: center;
-  margin: 10px;
+  margin: 10px 10px 10px -6px;
   width: 6px;
   height: 6px;
   border-radius: 3px;