bee-file/main, bee-join/main, api, api_test, file, file_test, netstore, netstore_test, node: add targets to query param on download path (#430)

* pkg/api,pkg/file,pkg/netstore: adds targets as query param to downloadfile and propagates the ctx all the way down to netstore

* cmd/bee-file,pkg/file: added missing context

* pkg/api added type for targets ctx

* pkg/netstore: commented out recovery section in netstore.get

* cmd/bee-join,pkg/api,pkg/netstore: simplified comment in netstore.get, changed targetsContextKey to struct and moved up to the package level

* api/test: added test for targets

* api,api_test: added test for targets

* api: removed antipattern

* api: changed targets location due to master conflicts

* api_test,api: added targets to chunk api and test for this use case

* api_test,netstore_test,netstore,node: refactored test for query param check and also integrated logs in netstore

* api_test: condensed targets test to minimal expression

* api,api_test: refactored Targets into swarm-recovery-targets and extracted it into api as a const

* api: fixed lint error space in comment

* netstore: removed todo from get