Even more geography buffer improvements

[irees]

closes interline-io/calact-network-analysis-tool#145

[Copilot]

Pull Request Overview

This PR enhances geography buffer functionality by adding dataset filtering support to census data operations. The changes enable more precise querying by allowing users to specify a particular census dataset when filtering geography data.

• Added dataset parameter to census geography filters and corresponding GraphQL schema
• Updated census value loading to include dataset filtering with null safety checks
• Refactored buffer query logic to improve performance with proper CTE usage and simplified join structure

Reviewed Changes

Copilot reviewed 6 out of 7 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
server/model/models_gen.go	Added optional Dataset field to CensusDatasetGeographyFilter struct
server/model/finders.go	Updated CensusValuesByGeographyIDs method signature to include dataset parameter
server/gql/loaders.go	Modified loader to handle dataset parameter with null safety and updated parameter structure
server/finders/dbfinder/finder.go	Removed unused checkRange function
server/finders/dbfinder/census.go	Enhanced geography queries with dataset filtering, improved buffer logic, and optimized database operations
schema/graphql/schema.graphqls	Added dataset input field to CensusDatasetGeographyFilter

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