⚡ Upgrade type checking

[pawelWritesCode]

Following methods:

AssertNodeIsType
AssertNodeIsNotType
AssertNodeIsTypeAndValue

accepts "nil", "string", "int", "float", "bool", "map", "slice" as type argument.

Methods should be able to detect data types related with JSON / YAML.

So, methods should now accept also following types:

JSON: null, array, object, number, boolean
YAML: scalar, list, dictionary

Currently accepted types should remain available for any data format.

Internal methods implementation should change. Required changes are:

Add new services container to APIContext: TypeMappers
TypeMappers container should contain fields: JSON, YAML, Go which holds services for corresponding formats.

Add new subpackage: types with Mapper interface definition and implementation for JSON, YAML and Go-like formats.