[web] introduce on click remove keyserver functionality

Summary:
This diff introduces onDeleteKeyserver callback which is fired whenever the delete keyserver button is clicked

For context here are the designs for what the user flow should look like:

Linear task: https://linear.app/comm/issue/ENG-5498/introduce-onpress-remove-selected-keyserver-function

Depends on D10081

Test Plan:
Please see the demo video below

Reviewers: rohan, inka, michal

Reviewed By: rohan

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D10089