Update GraphQL for Book Service Rename

[Feyzanrs]

We have recently renamed our 'Dlr' service to 'Book'. This change affects various components within our GraphQL setup. The task now is to update all relevant parts of the GraphQL codebase to reflect this new naming. This includes altering schemas, resolvers, and any other references from 'Dlr' to 'Book'. The goal is to ensure consistency across our entire backend infrastructure, aligning all service identifiers and related code to the new 'Book' naming convention. This will help maintain clarity in our codebase and prevent any future confusion.