Update nnn to 2.4

Summary:
Update nnn to 2.4

Partial Changelog

• FreeDesktop.org compliant trashing
• *wild* mode for *nav-as-you-type*
• POSIX-compliant GUI app launcher

Full changelog at https://github.com/jarun/nnn/releases/tag/v2.4

Test Plan:

• Check version: nnn -v
• Start nnn, try the following:
  • create/move/rename/delete a file
  • NEW: test wild mode using -w on launch
  • NEW: test gui launcher (key =)

Reviewers: Triage Team, JoshStrobl

Reviewed By: Triage Team, JoshStrobl

Differential Revision: https://dev.getsol.us/D5780