Start uniquely naming node default exports in generated code

[jakst]

Currently the default exports of queryname.graphql.ts and queryname$parameters.ts are simply named node. This makes it really cumbersome to work with import suggestions, as typing node will suggest every query in the whole project (see screenshot from VS Code).

Instead I suggest these exports get a unique name, so that the name of the query can be typed to get a single import suggestion from the IDE. Additionally the export could be exported as a named query in addition to the default export (to avoid breaking existing code).

Examples of names for the queries could be queryNameNode for queryName.graphql.ts and queryNamePreloadable for queryName$parameters.ts.