YAMLParser now supports YAML lists not parsed by the parser itself.

This means that list of type
```yaml
list:
  - test: "Hello"
  - test: "Hi"
```
will be parsed as a list of (ConfigurationSection)[src/main/java/it/fulminazzo/yamlparser/configuration/ConfigurationSection].
Totally reworked classes separation to respect packaging conventions.
Reworked FileConfiguration#addParsers method.
Renamed `it.fulminazzo.yamlparser.configurations` package to `it.fulminazzo.yamlparser.configuration`.
Made FileConfiguration and ConfigurationSection final.
Added support for escaped dot characters: now it will be able to use `\.` in paths to allow for dotted strings to be parsed.
Added support for BigDecimal notation when getting Number types.
Added `unquote` method to remove quoted strings when saving or loading.
Added `getOptional` method.
Now IConfiguration extends Serializable.
Reworked `FileConfiguration#newYaml` method to support older versions of SnakeYAML.
Fixed dotted test error.
Fixed `IConfiguration#getKeys` not returning an ordered set.
Fixed NullPointerException in `IConfiguration#throwException` method.
Fixed MapYAMLParser not supporting primitive types.
Fixed `FileConfiguration#getParser` method to look first for equal object classes.
Fixed `CollectionYAMLParser` not returning null values in non-specified indexes.
Updated README.md.
Updated FulmiCollection.

src/main/java/it/fulminazzo/yamlparser/configuration/IConfiguration.java

@@ -830,8 +830,7 @@ default boolean isList(@NotNull String path) {
         List<?> list = getObjectList(path);
         if (list == null) return null;
         return list.stream()
-                .filter(Objects::nonNull)
-                .map(o -> clazz.isAssignableFrom(o.getClass()) ? clazz.cast(o) :
+                .map(o -> o == null ? null : clazz.isAssignableFrom(o.getClass()) ? clazz.cast(o) :
                         convertObjectToYAMLObject(path, o, clazz))
                 .filter(o -> check(path, o, clazz))
                 .collect(Collectors.toList());