[native] factor keyserver list item into its own component

Summary:
Simple refactor diff. I want to separate this out into its own component since eventually we are going to add more logic like to open the bottomsheet on press and figured it would be better to have all that dedicated code in its own file rather than oversaturate the keyserver list component

Depends on D9724

Test Plan: flow and confirmed that everything still looks and behaves the same

Reviewers: inka, rohan, michal

Reviewed By: inka

Subscribers: ashoat, tomek, wyilio

Differential Revision: https://phab.comm.dev/D9725