[native] introduce showEmojiKeyboard shared value

Summary:
introduce showEmojiKeyboard shared value. This will be used to open/close the emoji keyboard and open/close the tooltip, which will be implemented in a subsequent diff.

Also noticed as developing that setHideTooltip would be better typed as SetState<boolean> so included that change in this diff.

Linear Task: ENG-2777

Test Plan: flow and diff will be further tested in subsequent diffs

Reviewers: atul, tomek

Reviewed By: tomek

Subscribers: ashoat, tomek, atul

Differential Revision: https://phab.comm.dev/D6445