[web] Rename NavigationTab -> WebNavigationTab

Summary:
Part of https://linear.app/comm/issue/ENG-6516/split-initialreduxstateresponse-into-client-and-server-variants

In order to move InitialReduxStateResponse to lib, we need to move NavInfo to lib.

In order to move NavInfo to lib, we need to move NavigationTab, LoginMethod, NavigationSettingsSection`, and NavigationChatMode to `lib.

Because those types are web-specific, we should give them a Web* prefix in lib. This is the first diff that does that for NavigationTab. Would've prefered to give them all the types the Web* prefix in one diff, but will break it up for easier review.

Test Plan: Straightforward rename, used IDE Refactor -> Rename tool.

Reviewers: ashoat, ginsu, tomek

Reviewed By: ginsu

Differential Revision: https://phab.comm.dev/D10886