wip mol-model/query

src/mol-model/structure/query.ts

src/mol-model/structure/query/context.ts

src/mol-model/structure/query/queries/combinators.ts

src/mol-model/structure/query/queries/filters.ts

src/mol-model/structure/query/queries/generators.ts

src/mol-model/structure/query/queries/modifiers.ts

src/perf-tests/tasks.ts