[lib] Allow calling message search from client

Summary: issue: https://linear.app/comm/issue/ENG-3170/create-a-keyserver-endpoint-for-the-message-search-within-specific

Test Plan:
called

dispatchActionPromise(
        searchMessagesActionTypes,
        this.props.searchMessages({
          threadID: inputThreadInfo.id,
          query: messageInfo.text,
        }),
      );

from input-state-container, checked with redux tools that start/success actions for message search appear, and that the success action has a correct payload containing the search results.

Reviewers: bartek, kamil, kuba, ashoat

Reviewed By: bartek, ashoat

Subscribers: ashoat, tomek, atul

Differential Revision: https://phab.comm.dev/D7652