feat: move query stats to backend and add missing types

src/frontend/statistics/graphStatistics.ts

src/frontend/statistics/index.ts

src/frontend/statistics/tests/attributeStats.spec.ts

src/frontend/statistics/tests/getAttributeType.spec.ts

src/frontend/statistics/tests/graphStatistics.spec.ts

src/frontend/statistics/utils/attributeStats/array.ts

src/frontend/statistics/utils/attributeStats/boolean.ts

src/frontend/statistics/utils/attributeStats/categorical.ts

src/frontend/statistics/utils/attributeStats/index.ts

src/frontend/statistics/utils/attributeStats/initialize.ts

src/frontend/statistics/utils/attributeStats/numerical.ts

src/frontend/statistics/utils/attributeStats/object.ts

src/frontend/statistics/utils/attributeStats/temporal.ts

src/frontend/statistics/utils/getAttributeType.ts

src/frontend/statistics/utils/index.ts

src/frontend/statistics/utils/updateStatistics.ts

src/readers/queryService.ts

src/utils/cypher/queryParser.ts