add deletePasswordUser to IdentityServiceClient

Summary:
mostly web and lib changes to add the identity client methods to the IdentityServiceClient interface

Depends on D11589

Test Plan: called the client methods on web and native through the respective context providers

Reviewers: tomek, bartek

Reviewed By: tomek, bartek

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D11590