TOOLS-4263 Delete JS tests fully covered by existing Go tests

Here's a mapping of JS to existing Go tests:

- test/legacy42/jstests/tool/tool1.js
    -> TestRoundTripBasicData (integration/exportimport/data_test.go)
       + TestPipedDumpRestore (integration/dumprestore/roundtrip_test.go)
- test/legacy42/jstests/tool/exportimport3.js
    -> TestRoundTripJSONArray (integration/exportimport/json_test.go)
- test/legacy42/jstests/tool/restorewithauth.js
    -> TestDumpRestoreEnforcesAuthRoles (mongorestore/dumprestore_auth_test.go)
- test/qa-tests/jstests/restore/users_and_roles_admin.js
    -> TestDumpRestoreSingleDBWithDBUsersAndRoles (mongorestore/dumprestore_auth_test.go)
- test/qa-tests/jstests/restore/stop_on_error.js
    -> TestMongorestoreMIOSOE (mongorestore/mongorestore_test.go)
- test/qa-tests/jstests/restore/oplog_replay_specify_file.js
    -> TestOplogRestore and related oplog-file cases (mongorestore/oplog_test.go)
- test/qa-tests/jstests/import/stoponerror.js
    -> TestImportMIOSOE (mongoimport/mongoimport_test.go)
- test/qa-tests/jstests/files/mongofiles_list.js
    -> "list" cases in TestMongoFilesCommands (mongofiles/mongofiles_test.go)

Author: autarch