feat(typescript): move typings inline (#719)

* chore: copy from DT

* made things required & prettier

removed duplication

* add field in package.json

* chore(dts): remove comment

* fix: accept any search client

* chore: comment

* fix: opts is optional

* fix(searchOnce): called with SearchParams

* fix: remove dropped methods

* type derive & detachDerived

* chore: prettier

* rename things

* remove getQueryParameter

* chore: simplify

* bye

* extend type correctly

* fix: MultiResponse misunderstanding

* better interface for SFFV

* fix Derived Helper

* lastResults can be null

* continue e508244

* plain parameters

* correct return from getQueryParams

* continue https://github.com/algolia/algoliasearch-helper-js/pull/719/files#r301510978

* add result to derived #719 (comment)