Split queries for defer directive

[bnjjj]

Related to #80

• Split main query into primary and deferred queries
• Rewrite the InlineFragment implementation
• Add support of static check for @include and @skip directives

The query is split regarding the @defer directive. If we could statically detect that the selection will be deferred then we just skip it from the primary selection. If not we will clone the selection into deferred_queries and also keep it in the primary query to be able to detect at the execution stage if it's a deferred selection or not.

TODO:

• To link a deferred node with a deferred query the main idea would be to specify a label on defer if not already provided, then in format response we just skip this label parameter if we detect that's one of our custom label